- PALLADIUM-CATALYZED ACYL-O BOND FISSION-PHENYLATION REACTION OF ALLYL ESTERS WITH BENZENE
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The palladium-catalyzed acyl-O bond fission-phenylation reaction of allyl esters with benzene has been found to give cinnamaldehyde derivatives in one step in modest yields.
- Fujiwara, Yuzo,Yoshidomi, Michiaki,Kuromaru, Hiroaki,Taniguchi, Hiroschi
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- Optimization of the Mizoroki-Heck reaction using Design of Experiment (DoE)
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The influence of the variables concentration, temperature, time, and amounts of base and palladium on the yield of a Heck reaction was investigated using statistical methods (DoE) in a systematic sequential study. This revealed that temperature, concentration, and amount of palladium were the most important variables with a factor interaction between temperature and concentration. Through this approach, the yield of the Heck reaction was improved from 57% to 98% (89% isolated) with concomitant reduction of palladium loading from 3% to 0.5%.
- Aggarwal, Varinder K.,Staubitz, Anne C.,Owen, Martin
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- Heck transformations of biological compounds catalyzed by phosphine-free palladium
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The development and optimization of synthetic methods leading to functionalized biologically active compounds is described. Two alternative pathways based on Heck-type reactions, employing iodobenzene or phenylboronic acid, were elaborated for the arylation of eugenol and estragole. Cinnamyl alcohol was efficiently transformed to saturated arylated aldehydes in reaction with iodobenzene using the tandem arylation/isomerization sequential process. The arylation of cinnamyl alcohol with phenylboronic acid mainly gave unsaturated alcohol, while the yield of saturated aldehyde was much lower. Catalytic reactions were carried out using simple, phosphine-free palladium precursors and water as a cosolvent, following green chemistry rules as much as possible.
- Tarnowicz-Ligus, Stanis?awa,Trzeciak, Anna M.
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- Oxime ligands for Pd catalysis of the Mizoroki–Heck reaction, Suzuki–Miyaura coupling & annulation reactions
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Monodentate and bidentate chelating oximes are readily available ligands for the Pd catalysis of the Mizoroki–Heck reaction and the Suzuki coupling. High yields were obtained in the Suzuki coupling in aqueous dioxane with TBABr as additive. The oximes can be easily synthesized from the corresponding ketones or aldehydes and thus provide a very large number of nitrogen-based ligands. They have the advantage of not undergoing oxidative degradation, common for phosphine ligands. Chelating oximes with Pd(OAc)2, activate aryl iodides to give high yields of the substitution products in the Mizoroki–Heck reactions as well as the Suzuki coupling. Acetophenone oxime ligand with Pd(OAc)2, catalyzed the reaction of aryl iodides with 1,2-disubstituted alkenes in moderate to high yields. As a test example, the LaRock indole annulation and synthesis of isocoumarin were achieved with acetophenone oxime ligand and Pd(OAc)2 in high yields.
- Bangar, Pronnoy G.,Nahide, Pradip D.,Meroliya, Heena K.,Waghmode, Shobha A.,Iyer, Suresh
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- Pd-catalysed arylation of propan-1-ol and derivatives: Oxidative role of the arylating agent
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With excess PhI under Pd catalysis, 1-PrOH was converted to a mixture of 3,3-diphenylpropenal and trans-2,3-diphenylpropenal by a concerted, oxidative sequence that involved two arylative couplings and an olefinic aldehyde that was generated in situ.
- Bagnell,Kreher,Strauss
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- Selenated NHC-Pd(II) catalyzed Suzuki-Miyaura coupling of ferrocene substituted β-chloro-cinnamaldehydes, acrylonitriles and malononitriles for the synthesis of novel ferrocene derivatives and their solvatochromic studies
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Suzuki-Miyaura coupling reaction between ferrocenyl/phenyl derivatives of (2-formyl-1-chlorovinyl)ferrocene, 3-chloro-3-ferrocenylacrylonitrile and (3-chloro-3-ferrocenylallylidene)malononitrile and arylboronic acid in the catalytic presence of a selenated NHC-Pd(II) full pincer complex was accomplished. Significantly, the couplings take place in water under normal atmospheric conditions, in contrast to many earlier reported Pd-catalysed reactions requiring inert atmosphere conditions. Solvatochromic studies of new ferrocene compounds revealed some interesting changes. Aggregation studies showed an increase of the absorbance with decrease of water content in the water/DMSO solvent mixture.
- Tomar, Vijesh,Upadhyay, Yachana,Srivastava, Avinash K.,Nemiwal, Meena,Joshi, Raj K.,Mathur, Pradeep
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supporting information
(2021/04/05)
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- Deep eutectic solvent-catalyzed Meyer-Schuster rearrangement of propargylic alcohols under mild and bench reaction conditions
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The Meyer-Schuster rearrangement of propargylic alcohols into α,β-unsaturated carbonyl compounds has been revisited by setting up an atom-economic process catalyzed by a deep eutectic solvent FeCl3·6H2O/glycerol. Isomerizations take place smoothly, at room temperature, under air and with short reaction times. The unique solubilizing properties of the eutectic mixture enabled the use of a substrate concentration up to 1.0 M with the medium being recycled up to ten runs without any loss of catalytic activity. This journal is
- Ríos-Lombardía, Nicolás,Cicco, Luciana,Yamamoto, Kota,Hernández-Fernández, José A.,Morís, Francisco,Capriati, Vito,García-álvarez, Joaquín,González-Sabín, Javier
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supporting information
p. 15165 - 15168
(2020/12/21)
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- Mizoroki–Heck reaction of 1,2-disubstituted aryl alkenes: Variables of synthesis, solvent and ligand modulation of reactivity
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Reaction of aryl iodides with 1,2-disubstituted aryl alkenes in the presence of TBABr/TBACl gave high yields of the Mizoroki–Heck product. Phosphine ligands were used for the modulation of reactivity and stereoselectivity, for the reaction of 4-iodoanisole with cinnamaldehyde. tert-Bu3P.HBF4 gave the highest E:Z ratio of 1:0.08. The use of PEG-200 and PEG-400 as solvent could activate the reaction of aryl iodides with various 1,2-disubstituetd aryl alkenes.
- Bangar, Pronnoy G.,Jawalkar, Priyanka R.,Dumbre, Swapnil R.,Raut, Pallavi K.,Patil, Dharmaraj J.,Tv, Neethu,Sudhakaran, Shana,Iyer, Suresh
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supporting information
p. 3796 - 3803
(2020/09/01)
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- Heck Reactions of Acrolein or Enones and Aryl Bromides – Synthesis of 3-Aryl Propenals or Propenones and Consecutive Application in Multicomponent Pyrazole Syntheses
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3-(Hetero)aryl propenals or propenones are efficiently prepared by a Heck reaction of (hetero)aryl bromides and acrolein or vinyl ketones using Beller's CataCXium Ptb ligand under Jeffery's and Fu's conditions. The formation of these three-carbon building blocks is embedded into consecutive three- and pseudo-four-component syntheses of 3-(hetero)aryl and 3,5-diarylpyrazoles with a broad substitution pattern in moderate to excellent yield.
- Stephan, Marvin,Panther, Jesco,Wilbert, Fabio,Ozog, Pauline,Müller, Thomas J. J.
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supporting information
p. 2086 - 2092
(2020/03/23)
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- Phosphorous acid promoted isomerization of propargyl alcohols to α,β-unsaturated carbonyl compounds
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A metal-free and two-phase protocol for the Meyer-Schuster isomerization of propargyl alcohols to the corresponding α,β-unsaturated carbonyl compounds has been achieved in the presence of stoichiometric phosphorous acid aqueous solution, which produces the desired products in high yields with excellent stereoselectivity. Compared with the traditional methods, the procedure features broad scope of the substrates, mild conditions, and easy separation, providing an appealing alternative to the Meyer-Schuster reaction.
- Gan, Xiaotang,Fu, Zuqi,Liu,Yan, Yani,Chen, Chao,Zhou, Yongbo,Dong, Jianyu
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- Preparation method of alpha, beta-unsaturated carbonyl compound
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The invention discloses a preparation method of an alpha, beta-unsaturated carbonyl compound. The preparation method is characterized by comprising the following steps: with substituted propargyl alcohol and water as substrates, performing Meyer-Schuster rearrangement under the catalysis of an MCM-41, SBA-15, USY, Beta or ZSM-5 acidic molecular sieve, filtering out a catalyst after completion of areaction and purifying to obtain a product, namely the alpha, beta-unsaturated carbonyl compound, wherein the mass ratio of the substituted propargyl alcohol, the ion-free water and the catalyst is 100:(10-150):(10-50). Compared with the prior art, the preparation method provided by the invention has the advantages as follows: according to the preparation method, a substrate has a wide application range, a catalytic system is free of an organic solvent, the catalyst is cheap, easy to produce, stable, free of pollution to the environment and recyclable, and the reaction yield is high.
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Paragraph 0026-0031
(2019/09/17)
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- Iron(III)/O2-Mediated Regioselective Oxidative Cleavage of 1-Arylbutadienes to Cinnamaldehydes
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A simple, efficient, and environmentally benevolent regioselective oxidative cleavage of 1-arylbutadienes to cinnamaldehydes mediated by iron(III) sulfate/O2 has been developed. The reaction offered good yields and excellent regioselectivity and showed good functional group tolerance (31 examples). The method is important, as few reports with limited substrate scope are available for such excellent oxidative cleavage of conjugated dienes.
- Bhowmik, Amit,Fernandes, Rodney A.
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supporting information
p. 9203 - 9207
(2019/11/14)
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- Palladium-Catalyzed Synthesis of β,β-Diaryl α,β-Unsaturated Ketones
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We herein describe a versatile palladium-catalyzed synthesis of β,β-diaryl α,β-unsaturated ketones. A broad range of aryl halides react with β-arylbutanones to afford biologically useful, symmetrical and unsymmetrical ketones. The use of 4,5-diazafluoren-9-one and oxygen makes this one-pot reaction more applicable. A plausible mechanism involving palladium-catalyzed oxidative Heck-type cross-coupling is also proposed.
- Zheng, Yi-Lin,Xiao, Li,Xie, Qiong,Shao, Li-Ming
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p. 1455 - 1465
(2019/03/07)
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- Silver sequestration of halides for the activation of Pd(OAc)2 catalyzed Mizoroki-Heck reaction of 1,1 and 1,2 - Disubstituted alkenes
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A ligand free catalytic system consisting of Pd(OAc)2 (cat) and stoichiometric quantities of silver salts, AgOAc or AgBF4, exhibit high efficiency in the Mizoroki-Heck arylation, transforming aryl iodides and 1,1 as well as 1,2 disubstituted alkenes into 1,1,2 – trisubstituted aryl alkenes in excellent yields in very short reaction times.
- Bangar, Pronnoy G.,Jawalkar, Priyanka R.,Dumbre, Swapnil R.,Patil, Dharmaraj J.,Iyer, Suresh
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- Hendrickson reagent induced rearrangement of aryl propargyl alcohols to α,β-unsaturated aldehydes
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The Hendrickson reagent (triphenylphosphonium anhydride trifluoromethanesulfonate), prepared from the reaction of triphenylphosphine oxide (Ph3PO) and triflic anhydride (Tf2O) (2:1 stoichiometry), promotes dehydrations and various coupling reactions. The reagent has been used to transform oximes to nitriles and to prepare esters, amides and many other functional groups through the intermediacy of an alkoxyphosphonium salt. The reagent proved useful in heterocycle synthesis of thiazolines, imidazolines, quinoline precursors, isoquinolines, β-carbolines, phenanthridines, 11H-indolo[3,2-c]quinolines, quinoline-lactones, furoquinolinones, and indolizino[1,2-b]quinolin-9(11H)-ones. Moreover, the reagent has been key to the successful total synthesis of several natural products. Aryl propargyl alcohols with a terminal α-acetylenic group undergo rapid conversion to the corresponding α,β-unsaturated aldehydes at room temperature in dichloromethane in the presence of one equivalent of triphenylphosphonium anhydride trifluoromethanesulfonate. The reaction involved adding freshly distilled Tf2O (1.0 mmol) to a solution of Ph3PO (2.0 mmol) in CH2Cl2 (10 mL) at 0oC under N2 atmosphere. After stirring for 10 min, the propargyl alcohol (1.0 mmol) was added as a CH2Cl2 solution (2 mL), followed by the addition of water and Et3N (2.0 mmol) and further stirring at room temperature for 1h. Subsequent workup with 5% NaHCO3 (20 mL) and purification afforded α,β-unsaturated aldehydes. Eighteen aryl propargyl alcohol substrates with a terminal α-acetylenic group were transformed in good to excellent yields (71-85%) to enals. The methodology proved successful with secondary and tertiary alcohols with stereoselectivity favouring exclusively the E isomer. All the synthesized compounds are known and were characterized (1H,13C, and M.P) and compared to literature values. The method offers several advantages such as exclusive stereoselectivity, short reaction time, good yield, mild reaction conditions, and simple operational procedure.
- Moussa, Ziad,Aljuhani, Ateyatallah
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p. 845 - 853
(2018/11/06)
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- Copper-catalyzed formylation of alkenyl C-H bonds using BrCHCl2 as a stoichiometric formylating reagent
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The first example of copper-catalyzed direct formylation of alkenyl C-H bonds for the facile synthesis of α,β-unsaturated aldehydes has been developed. This transformation has demonstrated high reactivity, mild reaction conditions and a broad substrate scope. BrCHCl2 is expected to be developed as an efficient stoichiometric C1 building block in organic synthesis.
- Bao, Yan,Wang, Gao-Yin,Zhang, Ya-Xuan,Bian, Kang-Jie,Wang, Xi-Sheng
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p. 2986 - 2990
(2018/03/23)
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- Metal- and Acid-Free Methyl Triflate Catalyzed Meyer-Schuster Rearrangement
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A novel metal- and acid-free preparation of synthetically useful α,β-unsaturated carbonyl compounds from propargyl alcohols has been realized. This Meyer-Schuster rearrangement process is effectively catalyzed by methyl triflate (20 mol%) to prepare a broad scope of conjugated E -enals and E -enones generally in good to excellent yields (up to 90%). This reaction procedure operates under mild conditions (70 °C), in air, with short reaction times (1 h). Moreover, a carbocation intermediate trapped by the solvent 2,2,2-trifluoroethanol was isolated during this transformation.
- Yang, Lu,Zeng, Qingle
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p. 3149 - 3156
(2017/07/12)
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- Phase-vanishing method applied to condensation reactions using TiCl4
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The phase-vanishing (PV) method using perfluorohexanes as the phase screen was applied to the aldol condensation using TiCl4 as the Lewis acid. A special test tube was used, in which an interface between the fluorous and organic layers was stirred, and cyclohexanone was treated with two equivalents of benzaldehyde derivatives under PV conditions to afford corresponding 2,6-dibenzylidencyclohexanone in good yields. The formyl-methylenation of ketones with triethylamine using TiCl4 was also demonstrated by the PV method.
- Adachi, Yusuke,Kuniyoshi, Kenji,Matsubara, Hiroshi
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p. 100 - 105
(2017/04/10)
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- Palladium-Catalyzed Cascade Saegusa–Heck Reaction: Synthesis of β,β-Diarylacroleins from Arylpropanals and Aryl Iodides
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An efficient and convenient Pd-catalyzed Saegusa–Heck cascade protocol was developed, and its potential use in the synthesis of symmetrical and unsymmetrical β,β-diarylacroleins in moderate to high yields was investigated.
- Xiao, Li,Zheng, Yilin,Xie, Qiong,Shao, Liming
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supporting information
p. 5880 - 5883
(2017/10/31)
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- Preparation method of alpha-beta-unsaturated carbonyl compound
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The invention relates to a preparation method of an alpha-beta-unsaturated carbonyl compound, in particular to a method in which the alpha-beta-unsaturated carbonyl compound is prepared from substitute propargyl alcohol in a mode that positive ion modified imvite serves as a catalyst, the substitute propargyl alcohol serves as the raw material, and Meyer-Schuster rearrangement is utilized. According to the method, the substrate is wide in application range, the catalyst is cheap, easy to manufacture, stable, free of pollution to the environment and capable of being recycled, the reaction yield is high, stereoselectivity is good, and an E-type product can be obtained in a singular mode.
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Paragraph 0103; 0104; 0105; 0106; 0107; 0108; 0109; 0110
(2016/10/09)
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- Cascade reaction of propargylic alcohols with hydroxylamine hydrochloride: facile synthesis of α,β-unsaturated oximes and nitriles
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We have developed an easy and practical method for the synthesis of α,β-unsaturated oximes and nitriles from readily available propargylic alcohols with hydroxylamine hydrochloride (NH2OH·HCl) under metal-free conditions. By using or not using p-toluenesulfonyl chloride (p-TsCl) as the dehydrating promoter, the desired nitriles or oximes could be obtained, respectively via a three-step one-pot or two-step one-pot process in moderate to excellent yields with good functional group compatibility.
- Zhang, Qi,Zhang, Linjing,Tang, Chaojun,Luo, Huan,Cai, Xuediao,Chai, Yonghai
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supporting information
p. 6935 - 6942
(2016/10/14)
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- Ruthenium(0)-Catalyzed C-H Arylation of Aromatic Imines under Neutral Conditions: Access to Biaryl Aldehydes
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The first ruthenium(0)-catalyzed C-H bond arylation of aromatic imines with arylboronates under neutral conditions is reported. This versatile method provides rapid access to a wide range of biaryl aldehydes that are difficult to assemble using traditional methods with high atom economy. A new hydrogen acceptor for Ru(0) arylation has been identified. This atom-economical strategy has potential for an array of direct applications in Ru(0)-catalyzed C-H bond arylations using removable directing groups. An indole synthesis by a sequential one-pot, multiple C-H activation protocol is reported.
- Hu, Feng,Szostak, Michal
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p. 4186 - 4189
(2016/09/09)
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- A Weinreb Amide Based Building Block for Convenient Access to β,β-Diarylacroleins: Synthesis of 3-Arylindanones
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Towards the synthesis of symmetrical and unsymmetrical β,β-diarylacroleins for assembling diarylmethine fragments present in biologically important molecules, we have developed a new Weinreb amide (WA) based building block, derived from propiolic acid. The WA functionality present in this compound allowed the sequential addition of various arylmagnesium bromide reagents in a controlled manner. The developed methodology for the access to β,β-diarylacroleins has been utilised for the synthesis of biologically important 3-arylindanone molecules. Synthesis of both symmetrical and unsymmetrical β,β-diarylacrolein and diarylmethine fragments, have been achieved via easily accessible and hitherto unknown Weinreb Amide (WA) based building block 11. The WA functionality allowed the sequential addition of nucleophiles such as arylmagnesium bromide in a controlled manner, which has enabled the synthesis of an important 3-arylindanone molecule.
- Tiwari, Praveen Kumar,Aidhen, Indrapal Singh
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p. 2637 - 2646
(2016/06/08)
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- Solvent-free hydration of alkynes over Hβ zeolite
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Abstract An efficient and environmentally benign catalytic system has been successfully developed for highly Markovnikov selective hydration of various alkynes over heterogeneous catalyst (Hβ zeolite) in solvent-free conditions. The catalyst (Hβ zeolite) is commercial available, recyclable and exhibits excellent catalytic activity towards the hydration of alkynes to ketones. Moreover, the propargylic aryl carbinols undergo Meyer-Schuster rearrangement to give α,β-unsaturated carbonyl compounds in excellent yields.
- Mameda, Naresh,Peraka, Swamy,Marri, Mahender Reddy,Kodumuri, Srujana,Chevella, Durgaiah,Gutta, Naresh,Nama, Narender
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p. 213 - 216
(2015/08/24)
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- Domino Reactions Containing Different Types of Heck Reactions for Selective 3,3- and 1,3-Diarylations of Propenol with Aryl Halides by Triple Catalysis
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A new domino Heck-isomerization/Saegusa/Heck reaction of propenol with aryl iodides has been developed for the synthesis of 3,3-diaryl propenals by triple transition-metal catalysis. Moreover, we also developed the domino Heck-isomerization/Heck-type reaction of propenol with aryl iodides for the synthesis of 1,3-diaryl propanones by double transition-metal catalysis and the mediation of secondary amine or triple transition metal catalysis and aminocatalysis.
- Zhu, Zhi-Qiang,He, Jian-Shi,Wang, Hai-Jun,Huang, Zhi-Zhen
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supporting information
p. 9354 - 9359
(2015/09/28)
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- Ferrocenium hexafluorophosphate as an inexpensive, mild catalyst for the etherification of propargylic alcohols
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Commercial ferrocenium hexafluorophosphate ([FeCp2]PF6) was found to be an efficient catalyst for the etherification of terminal, tertiary propargylic alcohols with primary and secondary alcohols (5 h to 3 days reaction time at 40 °C in CH2Cl2, 3 mol% catalyst loading). The propargylic ether products were isolated in 90-20% yields. The alcohols and propargylic alcohols were employed in an equimolar amount and no further additives were required. For a purely aromatic propargylic alcohol, the isolated yields were lower than those for a mixed aromatic-aliphatic propargylic alcohol. Through monitoring reactant consumption and product formation over time, we found that the aromatic propargylic alcohol undergoes yield-diminishing Meyer-Schuster rearrangements to the aldehyde more easily than the mixed aromatic-aliphatic propargylic alcohol. The employment of [Fe(Cp)2]PF6 as a single electron oxidant has the potential to add a new direction in the development of catalysts for the title reaction based on single electron transfer processes.
- Queensen, Matthew J.,Rabus, Jordan M.,Bauer, Eike B.
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p. 221 - 229
(2015/08/06)
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- Bulky, spherical, and fluorinated anion BArF induces 'on-water' activity of silver salt for the hydration of terminal alkynes
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AgBArF displays remarkable 'on-water' activity for catalytic hydration of terminal alkynes although it is ineffective in common organic solvents. Liquid alkynes do not require additive or co-solvent whereas a small amount of ethyl acetate triggers quantitative conversions for solid alkynes.
- Saha, Sayantani,Sarbajna, Abir,Bera, Jitendra K.
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supporting information
p. 1444 - 1447
(2014/03/21)
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- [PF6]2 As catalyst for the meyer-schuster rearrangement of arylpropargylic alcohols under mild conditions
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The novel iridium complex [IrCpNCMe2PPh2Me][PF6]2 I efficiently catalyzed the Meyer-Schuster rearrangement of selected arylpropargylic alcohols into α,β-unsaturated aldehydes under mild conditions and without the need of a co-catalyst. A mechanism involving a hydroxy alkenylcarbene intermediate is proposed. [IrCpNCMe2PPh2Me][PF6]2 efficiently catalyzes the rearrangement of propargylic alcohols into α,β-unsaturated aldehydes under mild conditions and without the need of a co-catalyst.
- Talavera, María,Bravo, Jorge,Gonsalvi, Luca,Peruzzini, Maurizio,Zuccaccia, Cristiano,Bola?o, Sandra
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p. 6268 - 6274
(2015/02/19)
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- Palladium-catalyzed dehydrogenative β-arylation of simple saturated carbonyls by aryl halides
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(Chemical Equation Presented) A versatile palladium-catalyzed synthesis of highly substituted α,β-unsaturated carbonyl compounds has been developed. In contrast to the known Heck-type coupling reaction of unsaturated carbonyl compounds with aryl halides, the present methodology allows the use of stable and readily available saturated carbonyl compounds as the alkene source. In addition, the reaction proceeds well with low catalyst loadings and does not require any expensive metal oxidants or ligands. A variety of saturated aldehydes, ketones, and esters are compatible for the reaction with aryl halides under the developed reaction conditions to afford α,β-unsaturated carbonyl compounds in good to excellent yields. A possible reaction mechanism involves a palladium-catalyzed dehydrogenation followed by Heck-type cross couplings.
- Gandeepan, Parthasarathy,Rajamalli,Cheng, Chien-Hong
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p. 4485 - 4489
(2015/01/09)
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- Palladium-catalyzed oxidative rearrangement of tertiary allylic alcohols to enones with oxygen in aqueous solvent
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A one-pot procedure for Pd(TFA)2-catalyzed 1,3-isomerization of tertiary allylic alcohols to secondary allylic alcohols followed by a Pd(TFA)2/neocuproine-catalyzed oxidative reaction to β-disubstituted-α,β-unsaturated kenones was developed. (Chemical Equation Presented).
- Li, Jingjie,Tan, Ceheng,Gong, Jianxian,Yang, Zhen
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supporting information
p. 5370 - 5373
(2015/01/09)
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- Thermal intramolecular [2 + 2] cycloaddition: Synthesis of 3-azabicyclo[3.1.1]heptanes from morita-baylis-hillman adduct-derived 4,4-diaryl-1,3-dienes
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Various 3-azabicyclo[3.1.1]heptane derivatives were synthesized from Morita-Baylis-Hillman adduct-derived 1,3-dienes bearing a 4,4-diaryl moiety through a thermal intramolecular [2+2] cycloaddition approach. By using the same approach, bicyclo[3.1.1]heptane, 3-azabicyclo[3.2.0]heptane, and 3-oxabicyclo[3.1.1]heptane derivatives could also be synthesized. A structurally similar dimethyl-Gallyl derivative underwent an intramolecular ene reaction to afford the pyrrolidine derivative.
- Kim, Ko Hoon,Lim, Jin Woo,Lee, Junseung,Go, Min Jeong,Kima, Jae Nyoung
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supporting information
p. 3363 - 3369
(2015/02/02)
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- Assembly of indenamine derivatives through in situ formed N-sulfonyliminium ion initiated cyclization
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An expedient route to structurally diverse indenamine derivatives through condensation of the readily accessible substituted cinnamylaldehydes and sulfonylamines under the catalysis of FeCl3 has been developed, featuring high efficiency in the generation of two bonds and one ring in a single-step and water as the only by-product. This journal is the Partner Organisations 2014.
- Fan, Xiaohui,Lv, Hao,Guan, Yong-Hong,Zhu, Hong-Bo,Cui, Xiao-Meng,Guo, Kun
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supporting information
p. 4119 - 4122
(2014/04/03)
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- New Ag(I)-iminophosphorane coordination polymers as efficient catalysts precursors for the MW-assisted meyer-schuster rearrangement of propargylic alcohols in water
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Treatment of the N-thiophosphorylated iminophosphorane ligands (PTA)=NP(=S)(OR)2 [PTA = 1,3,5-triaza-7-phosphaadamantane, 3a and 3b] and (DAPTA)=NP(=S)(OR)2 [DAPTA = 3,7-diacetyl-1,3,7-triaza-5- bicyclo[3.3.1]nonane, 4a and 4b] with an equimolecular amount of AgSbF 6 leads to high-yield formation of the new one-dimensional coordination polymers [Ag{μ2-N,S-(PTA)=NP(=S)(OR) 2}]x[SbF6]x (5a and 5b) and [Ag{μ2-O,S-(DAPTA)=NP(=S)(OR)2}]x[SbF 6]x (6a and 6b), respectively. These new (iminophosphorane)silver(I) coordination polymers are efficient catalyst precursors for the Meyer-Schuster isomerization of both terminal and internal alkynols. Reactions proceeded in water, under aerobic conditions and using microwave irradiation as heating source, to afford the corresponding α,β-unsaturated carbonyl compounds in excellent yields, without the addition of any cocatalyst. Remarkably, it should be noted that this catalytic system can be recycled up to 10 consecutive runs (1st cycle 45 min, 99%; 10th cycle 6 h, 97%). ESI-MS analysis of 5a in water has been carried out providing valuable insight into the monomeric active species responsible for catalytic activity in water.
- Garcia-Alvarez, Joaquin,Diez, Josefina,Vidal, Cristian,Vicent, Cristian
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p. 6533 - 6542
(2013/07/19)
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- Synthesis and reactivity of new rhenium(I) complexes containing iminophosphorane-phosphine ligands: Application to the catalytic isomerization of propargylic alcohols in ionic liquids
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[ReBr(CO)5] reacts with the iminophosphorane-phosphine ligands Ph2PCH2P(=NR)Ph2 (R = P(=O)(OEt)2 (1a), P(=O)(OPh)2 (1b), P(=S)(OEt)2 (1c), P(=S)(OPh) 2 (1d), 4-C6F4CHO (1e), 4-C6F 4CN (1f), 4-C5F4N (1g)) affording the neutral complexes [ReBr(κ2-P,X-Ph2PCH2P{=NP(=X) (OR)2}Ph2)(CO)3] (X = O, R = Et (2a), Ph (2b); X = S, R = Et (2c), Ph (2d)) and [ReBr{κ2-P,N-Ph 2PCH2P(=NR)Ph2}(CO)3] (R = P(=O)(OEt)2 (3a), P(=O)(OPh)2 (3b), 4-C6F 4CHO (3e), 4-C6F4CN (3f), 4-C5F 4N (3g)). The reactivity of the cationic complex [Re(κ 3-P,N,S-Ph2PCH2P{=NP(=S)(OPh) 2}Ph2)(CO)3][SbF6] (4d) has been explored allowing the synthesis of the cationic [Re(L)(κ2-P,S- Ph2PCH2P{=NP(=S)(OPh)2}Ph2)(CO) 3][SbF6] (L = acetone (5a), CH3C≡N (5b), pyridine (5c), PPh3 (5d)) and the neutral [ReY(κ2-P, S-Ph2PCH2P{=NP(=S)(OPh)2}Ph2)(CO) 3] (Y = Cl (6a), I (6b), N3 (6c)) complexes. The catalytic activity of complex 4d in the regioselective isomerization of terminal propargylic alcohols HC≡CCR1R2(OH) into α,β-unsaturated aldehydes R1R2C=CHCHO or ketones R3R4C=CR1COMe (if R2 = CHR3R4) under neutral conditions in ionic liquids has being studied. Isolation and X-ray characterization of the key intermediate rhenium(I) oxocyclocarbene complex [Re{=C(CH2)3O} (κ2-P,S-Ph2PCH2P{=NP(=S)(OPh) 2}Ph2)(CO)3][SbF6] (5e) seems to indicate that the catalytic reaction proceeds through tautomerization of the terminal alkynols to yield vinilydene-type species.
- Garcia-Alvarez, Joaquin,Diez, Josefina,Gimeno, Jose,Seifried, Christine M.,Vidal, Cristian
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supporting information
p. 5428 - 5437
(2013/06/26)
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- The indium-catalysed hydration of alkynes using substoichiometric amounts of PTSA as additive
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A general, efficient and highly regioselective protocol using an indium(III) trifluoromethanesulfonate and PTSA (TsOH·H2O) catalytic system for the transformation of various alkynes to the corresponding ketones has been successfully developed.
- Gao, Qi,Li, Shenyan,Pan, Yingming,Xu, Yanli,Wang, Hengshan
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supporting information
p. 3775 - 3781
(2013/06/26)
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- Pd-arylurea complexes for the Heck arylation of crotonic and cinnamic substrates
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A catalyst consisting of the 1:2 complex of Pd(OAc)2 (1 mol %) with N-(4-carbethoxy)-phenylurea promotes the Heck arylation of a range of crotonic and cinnamic substrates, including aldehydes, ketones, esters, and nitriles, with electron-rich - but not electron-deficient - aryl iodides.
- Smith, Matthew R.,Kim, Jung Yun,Ciufolini, Marco A.
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p. 2042 - 2045
(2013/04/24)
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- Selective reactivity of electron-rich aryl iodides in the Heck arylation of disubstituted alkenes catalyzed by palladium-arylurea complexes
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A catalyst consisting of 1 mol % of the 1:2 complex of Pd(OAc)2 with N-(4-carbethoxyphenyl)urea promotes the Heck arylation of 2- or 3-substituted, conjugated esters, nitriles, aldehydes, and ketones (an uncharacteristically broad range of substrates), but only with electron-rich aryl iodides (an uncharacteristically narrow range of halides).
- Smith, Matthew R.,Jang, Young Jin,Kim, Jung Yun,Ciufolini, Marco A.
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p. 10139 - 10151
(2013/11/06)
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- Mild chemo-selective hydration of terminal alkynes catalysed by AgSbF 6
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The chemo-selective hydration of a wide range of non-activated terminal alkynes catalysed by AgSbF6 under mild conditions is reported.
- Thuong, Mathieu Bui The,Mann, Andre,Wagner, Alain
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supporting information; experimental part
p. 434 - 436
(2012/01/05)
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- Novel rhenium(i) catalysts for the isomerization of propargylic alcohols into α,β-unsaturated carbonyl compounds: An unprecedented recyclable catalytic system in ionic liquids
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Carbonyl rhenium(i) complexes are efficient catalysts for the regioselective isomerization of terminal propargylic alcohols into α,β-unsaturated aldehydes or ketones which can be used as an unprecedented recyclable catalytic system (up to 10 consecutive runs) in the ionic liquid [BMIM][PF6].
- Garcia-Alvarez, Joaquin,Diez, Josefina,Gimeno, Jose,Seifried, Christine M.
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supporting information; scheme or table
p. 6470 - 6472
(2011/07/09)
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- Iron(III) chloride-promoted isomerization of propargyl alcohols to α,β-unsaturated carbonyl compounds
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Aryl propargyl alcohols bearing a terminal alkynyl moiety can undergo a facile iron(III) chloride-promoted transformation to the corresponding α,β-unsaturated aldehyde in good yield and excellent stereoselectivity.
- El Douhaibi, Ahmad Samih,Judeh, Zaher M. A.,Basri, Hedaya,Moussa, Ziad,Messali, Mouslim,Qi, Gao
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experimental part
p. 533 - 540
(2011/04/22)
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- The Heck arylation of mono- and disubstituted olefins catalyzed by palladium supported on alumina-based oxides
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Palladium catalysts containing Pd(0) or Pd(II) supported on alumina-based mixed oxides prepared by alkoxide sol-gel method (Al2O3, Al2O3-ZrO2, Al2O3- ZrO2-Eu2O3, Al2O3-MgO, Al2O3-CeO2, Al2O3-Fe 2O3) are very effective in the Heck coupling of bromobenzene with butyl acrylate in DMF solvent. In the presence of an excess of bromobenzene, butyl cinnamate (1) was formed as the main product after 4 h. With the same catalysts, good results, up to 97% yield of ethyl β-phenylcinnamate (3), were also obtained in the coupling of bromobenzene with ethyl cinnamate. The three most active catalysts, Pd(0)/Al 2O3, Pd(II)/Al2O3, and Pd(II)/Al2O3-Fe2O3, were applied in the Heck cross-coupling of cinnamates with different bromobenzene and iodobenzene derivatives, leading to β-arylcinnamate products. The highest yield was observed when iodoanisole and cinnamic aldehyde were used as substrates. The formation of Pd(0) nanoparticles in the Heck reaction carried out with supported Pd(II) catalyst precursors was confirmed by TEM measurements.
- Mieczyńska, Ewa,Gniewek, Andrzej,Pryjomska-Ray, Iweta,Trzeciak, Anna M.,Grabowska, Hanna,Zawadzki, Miros?aw
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scheme or table
p. 195 - 205
(2011/10/30)
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- Pd-diimine: A highly selective catalyst system for the base-free oxidative heck reaction
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Pd(OAc)2/3 is an efficient catalyst system for the base-free oxidative Heck reaction that outperforms the currently available catalysts for the more challenging substrates studied. The catalyst system is highly selective, and works at room temperature with dioxygen as the oxidant.
- Gottumukkala, Aditya L.,Teichert, Johannes F.,Heijnen, Dorus,Eisink, Niek,Van Dijk, Simon,Ferrer, Catalina,Van Den Hoogenband, Adri,Minnaard, Adriaan J.
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supporting information; experimental part
p. 3498 - 3501
(2011/06/22)
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- Preparation of thiolate-bridged dinuclear ruthenium complexes bearing a phosphine ligand and application to propargylic reduction of propargylic alcohols with 2-propanol
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Novel thiolate-bridged dinuclear ruthenium complexes bearing a phosphine ligand, [CpRu{PhP(C6H4-o-S)2}RuCp](OTf) 2, [CpRu{PhP(C6H4-o-S)2}RuCp(OH 2)](OTf)2, and [CpFe{PhP(C6H 4-o-S)2}RuCp](OTf)2, are prepared and characterized by X-ray analysis. These dinuclear complexes work as effective catalysts toward propargylic reduction of propargylic alcohols with 2-propanol via allenylidene complexes as key intermediates to give the corresponding alkynes in good to high yields.
- Yuki, Masahiro,Miyake, Yoshihiro,Nishibayashi, Yoshiaki
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experimental part
p. 5994 - 6001
(2011/02/27)
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- A simple and versatile re-catalyzed meyer-schuster rearrangement of propargylic alcohols to α,β-unsaturated carbonyl compounds
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The development of a general catalytic procedure for the rapid and efficient 1,3-rearrangement of free secondary and tertiary propargylic alcohols to the corresponding α,β-unsaturated carbonyl compounds using available [ReOCl3(OPPh3)-(SMe2)] complex, was reported. The reaction was carried out under neutral environmental conditions with no racemization of potentially enolizable stereocenters with virtually complete E stereoselectivity. The reaction under dimethoxyethane, proceeded at the lower rate than in THF, but with reduced by-products and the yield obtained were highly significant. The reaction was reported to increase constantly at the expense of the (Z)-isomer 2b, where the double bong isomerization was attributed to a catalytic effect of the rhenium complex. The resulted new version of Meyer-Schuster rearrangement will find enormous application in organic synthesis to develop one-pot multistep reaction sequences.
- Stefanoni, Massimo,Luparia, Marco,Porta, Alessio,Zanoni, Giuseppe,Vidari, Giovanni
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experimental part
p. 3940 - 3944
(2009/12/03)
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- Microwave-assisted InCl3-catalyzed Meyer-Schuster rearrangement of propargylic aryl carbinols in aqueous media: a green approach to α,β-unsaturated carbonyl compounds
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A novel, efficient, simple and environmentally benign protocol for the Meyer-Schuster isomerization of propargylic aryl carbinols into α,β-unsaturated carbonyl compounds has been developed using catalytic amounts of InCl3, pure water as the solvent, and microwave irradiation as the heating source.
- Cadierno, Victorio,Francos, Javier,Gimeno, José
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experimental part
p. 4773 - 4776
(2011/03/19)
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- Catalytic reactions of carbene precursors on bulk gold metal
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Bulk gold metal powder, consisting of particles (5-50 μm) much larger than nanoparticles, catalyzes the coupling of carbenes generated from diazoalkanes (R2C=N2) and 3,3-diphenylcyclopropene (DPCP) to form olefins. It also catalyzes cyclopropanation reactions of these carbene precursors with styrenes. The catalytic activity of the gold powder depends on the nature of the gold particles, as determined by TEM and SEM studies. The reactions can be understood in terms of mechanisms that involve the generation of carbene R2C: intermediates adsorbed on the gold surface.
- Zhou, Yibo,Trewyn, Brian G.,Angelici, Robert J.,Woo, L. Keith
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supporting information; experimental part
p. 11734 - 11743
(2009/12/08)
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- Simple one-pot conversion of aldehydes and ketones to enals
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A simple and efficient method to convert aldehydes into α,β-unsaturated aldehydes with a two-carbon homologation is presented. Hydroboration of ethoxy acetylene with BH3·SMe 2 generates tris(ethoxyvinyl) borane. Transmetalation with
- Valenta, Petr,Drucker, Natalie A.,Bode, Jeffrey W.,Walsh, Patrick J.
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supporting information; experimental part
p. 2117 - 2119
(2009/10/18)
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- [(NHC)AuI]-catalyzed formation of conjugated enones and enals: An experimental and computational study
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The [(NHC)AuI]-catalyzed (NHC = N-heterocyclic carbene) formation of α,β-unsaturated carbonyl compounds (enones and enals) from propargylic acetates is described. The reactions occur at 60°C in 8 h in the presence of an equimolar mixture of [(NHC)AuCl] and AgSbF6 and produce conjugated enones and enals in high yields. Optimization studies revealed that the reaction is sensitive to the solvent, the NHC, and, to a lesser extent, to the silver salt employed, leading to the use of [(ItBu)AuCl]/ AgSbF6 in THF as an efficient catalytic system. This transformation proved to have a broad scope, enabling the stereoselective formation of (E)-enones and -enals with great structural diversity. The effect of substitution at the propargylic and acetylenic positions has been investigated, as well as the effect of aryl substitution on the formation of cinnamyl ketones. The presence or absence of water in the reaction mixture was found to be crucial. From the same phenylpropargyl acetates, anhydrous conditions led to the formation of indene compounds via a tandem [3,3] sigmatropic rearrangement/intramolecular hydroarylation process, whereas simply adding water to the reaction mixture produced enone derivatives cleanly. Several mechanistic hypotheses, including the hydrolysis of an allenol ester intermediate and SN2′ addition of water, were examined to gain an insight into this transformation. Mechanistic investigations and computational studies support [(NHC)AuOH], produced in situ from [(NHC)AuSbF6] and H 2O, instead of cationic [(NHC)AuSbF6] as the catalytically active species. Based on DFT calculations performed at the B3LYP level of theory, a full catalytic cycle featuring an unprecedented transfer of the OH moiety bound to the gold center to the C≡C bond leading to the formation of a gold-allenolate is proposed.
- Marion, Nicolas,Carlqvist, Peter,Gealageas, Ronan,De Fremont, Pierre,Maseras, Feliu,Nolan, Steven P.
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p. 6437 - 6451
(2008/02/13)
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- Activation of mononuclear arene ruthenium complexes for catalytic propargylation directly with propargyl alcohols
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Mononuclear complexes of the type [(p-cymene)RuX(CO)(PR3)][OTf] (R = Ph, Cy; X = Cl, OTf) promote the direct catalytic propargylation of furan with propargyl alcohols. These precursors are generated in situ from [(p-cymene)RuCl(OTf)(PR3)] by activation of the propargylic alcohol, leading to the carbonyl ligand formation via allenylidene and alkenyl-hydroxycarbene intermediates. The generation of the catalytically active species requires a short initial thermal activation to induce decoordination of the p-cymene ligand. The in situ generated catalyst has been applied to catalytic transformations of alkynes and propargylic alcohols: propargylation of furans, propargyl ether synthesis from internal and terminal propargylic alcohols with propargyl, homopropargyl and allyl alcohols, selective dimerization of phenylacetylene into E-enyne, and propargyl alcohol rearrangement into α,β-unsaturated aldehydes and ketones via the Meyer-Schuster rearrangement. The propargylation of propargylic alcohols containing internal C≡C bonds suggests an activation via the Nicholas-type intermediate, the metalstabilized propargyl cation.
- Bustelo, Emilio,Dixneuf, Pierreh H.
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p. 933 - 942
(2008/03/27)
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- Isomerization of propargylic alcohols into α,β-unsaturated carbonyl compounds catalyzed by the sixteen-electron allyl-ruthenium(II) complex [Ru(η3-2-C3H4Me)(CO)(dppf)] [SbF 6]
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The 16-e- (η3-allyl)-ruthenium(II) complex [Ru(η3-2-C3H4Me)(CO)(dppf)][SbF 6] is an efficient catalyst for the regioselective isomerization of terminal propargylic alcohols HC≡CCR1R2(OH) into α,β-unsaturated aldehydes R1R2C=CHCHO or ketones R3R4C=C(R1)COMe (if R2 = CHR3R4) under mild conditions. This complex has been also used as catalyst for the preparation of conjugated 1,3-enynes via dehydration of propargylic alcohols.
- Cadierno, Victorio,Garcia-Garrido, Sergio E.,Gimeno, Jose
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p. 101 - 110
(2007/10/03)
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- Synthesis and NMR spectroscopic characterization of some fluoro-2H-1-benzopyran derivatives
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The synthesis of some new fluoro-2H-1-benzopyran derivatives utilizing a reaction between titanium phenolates and β-phenylcinnamaldehydes in toluene is reported. These compounds were characterized by NMR and UV/visible spectroscopy as well as mass spectrometry. In solution all the compounds are photochromic. Complete assignment of the 1H and 13C resonances was achieved by concerted application of homonuclear (gs-COSY), proton-detected (C, H) one-bond (gs-HMQC), and long-range (gs-HMBC) heteronuclear two-dimensional chemical shift correlation experiments using a 500 MHz NMR spectrometer equipped with a cryoplatform and a 5 mm cryoprobe. The mass spectra of the different compounds were characterized by intense molecular and high fragment ions. The introduction of an atom of fluorine as a molecular probe is of interest in determining the mechanistic aspects of the photochemical process. CSIRO 2005.
- Teral, Yannick,Roubaud, Gabriel,Aubert, Claude,Faure, Robert,Campredon, Mylene
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p. 517 - 521
(2007/10/03)
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