cas 25333-24-8, METHYL 3-BENZOYLPROPIONATE

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3,6-bis(triphenylphosphonium)cyclohexene peroxodisulfate: A highly efficient oxidant for the selective oxidation of benzylic alcohols
The synthesis of 3,6-bis(triphenylphosphonium)cyclohexene peroxodisulfate and its application for the selective oxidation of benzylic alcohols is reported.
Badri,Shalbaf,Heidary
p. 3473 - 3479
(2001)
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Reaction of iron aminocarbene complexes with electronically deficient alkenes
Thermal reaction of iron aminocarbene complexes bearing aromatic substituent (CO)4Fe=C(Ar)N(CH3)2 with methyl acrylate, acrylonitrile and methyl vinyl ketone furnishes 1,4-dicarbonyl compounds - formal products of Michael
Rotrekl, Ivan,Vyklicky, Libor,Dvorák, Dalimil
p. 329 - 333
(2001)
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Photoinduced Deaminative Alkylation for the Synthesis of γ-Ketoesters via Electron Donor–Acceptor Complex Formation
Visible-light-induced deaminative alkylation of Katritzky salts with silyl enol ethers has been developed. The reaction can proceed efficiently through electron donor–acceptor complex formation, avoiding the use of precious metal complexes or synthetically elaborate organic dyes. A series of functionalized γ-ketoesters was successfully obtained with good functional group tolerance and compatibility under mild and straightforward conditions.
Wang, Jia-Xin,Ge, Wei,Xing, Wei-Long,Fu, Ming-Chen
supporting information
p. 18224 - 18231
(2021/12/13)

Metal-free reduction of unsaturated carbonyls, quinones, and pyridinium salts with tetrahydroxydiboron/water
A series of unsaturated carbonyls, quinones, and pyridinium salts have been effectively reduced to the corresponding saturated carbonyls, dihydroxybenzenes, and hydropyridines in moderate to high yields with tetrahydroxydiboron/water as a mild, convenient, and metal-free reduction system. Deuterium-labeling experiments have revealed this protocol to be an exclusive transfer hydrogenation process from water. This journal is
Li, Tiejun,Peng, Henian,Tang, Wenjun,Tian, Duanshuai,Xu, Guangqing,Yang, He
p. 4327 - 4337
(2021/05/31)

Tandem homologation-acylation chemistry: Single and double homologation
Treatment of β-dicarbonyls with the Furakawa-variant of the Simmons-Smith reagent results in homologation and production of an intermediate zinc enolate. Treatment of the enolate with various acylating agents generate products with both γ-dicarbonyl funct
Henderson, Carley S.,Mazzone, Jennifer R.,Moore, Amanda M.,Zercher, Charles K.
supporting information

(2021/06/01)

Visible-Spectrum Solar-Light-Mediated Benzylic C-H Oxygenation Using 9,10-Dibromoanthracene As an Initiator
We report a visible-light-mediated benzylic C-H oxygenation reaction. The reaction is initiated by solar light or the blue LED activation of 9,10-dibromoanthracene in a reaction with oxygen and takes place at ambient temperature and air pressure. Secondary benzylic positions are oxygenated to ketones, while tertiary benzylic carbons are oxygenated to give hydroperoxides. Notably, cumene hydroperoxide is produced in a higher yield and at milder conditions than the currently employed industrial conditions.
Santra, Sourav K.,Szpilman, Alex M.
p. 1164 - 1171
(2020/12/23)

LIGHT INDUCED CATALYTIC C-H OXYGENATION OF ALKANES
A method of oxygenating a benzylic C-H bond is provided. The method comprises light induced activation of an initiator and subsequent reaction with oxygen, resulting in the formation of free radicals. Subsequently, free radicals catalyze the reaction of the benzylic C-H bond with oxygen, thereby forming an oxygenated compound.
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(2021/04/02)

Direct Synthesis of Chiral NH Lactams via Ru-Catalyzed Asymmetric Reductive Amination/Cyclization Cascade of Keto Acids/Esters
Lactams with a stereogenic center adjacent to the N atom have existed in many medicinal agents and bioactive alkaloids. Herein we report a broadly applicable synthesis of enantioenriched NH lactams through a one-pot asymmetric reductive amination/cyclization sequence of easily available keto acids/esters. Such cascade processes alleviate the demand for protecting group manipulations as well as intermediate purification. This strategy is capable of constructing enantioenriched lactams and benzo-lactams of a five-, six-, or seven-membered ring in generally high yield and with excellent enantioselectivities (up to 97% ee). Scalable and concise syntheses of key drug intermediates have further displayed the importance of this methodology.
Shi, Yongjie,Tan, Xuefeng,Gao, Shuang,Zhang, Yao,Wang, Jingxin,Zhang, Xumu,Yin, Qin
supporting information
p. 2707 - 2713
(2020/03/30)

Biocatalytic Asymmetric Reduction of γ-Keto Esters to Access Optically Active γ-Aryl-γ-butyrolactones
An efficient stereoselective syntheses of a series of functionalized optically active γ-aryl-γ-butyrolactones is achieved by enzymatic asymmetric reduction of the corresponding sterically demanding γ-keto esters employing wild-type and recombinant alcohol dehydrogenases. The best stereoselectivities for the reduction via hydrogen transfer was obtained with two short chain dehydrogenases (SDRs) of complementary stereospecificity from Aromatoleum aromaticum, namely the Prelog-specific NADH-dependent (S)-1-phenylethanol dehydrogenase [(S)-PED] and the anti-Prelog-specific (R)-1-(4-hydroxyphenyl)-ethanol dehydrogenase [(R)-HPED], respectively.Biotransformations catalyzed by both enzymes, followed by TFA-catalyzed cyclization of the resulting γ-hydroxy esters, furnished the respective (S)- and (R)-configured products with exquisite optical purity (up to >99% ee). The synthetic value was demonstrated on preparative scale for the asymmetric bioreduction of the model compound, methyl 4-oxo-4-phenylbutanoate, affording optically pure (S)-γ-phenyl-γ-butyrolactone (>99% ee) in 67–74% isolated yield at 89–95% conversion depending on the applied scale. (Figure presented.).
??d?o-Dobrowolska, Anna,Borowiecki, Pawe?,Heider, Johann,Kroutil, Wolfgang,Reiter, Tamara,Schühle, Karola,Szaleniec, Maciej,Tataruch, Mateusz,Telatycka, Natalia
(2020/04/20)

Photoredox-Catalyzed Isomerization of Highly Substituted Allylic Alcohols by C?H Bond Activation
Photoredox-catalyzed isomerization of γ-carbonyl-substituted allylic alcohols to their corresponding carbonyl compounds was achieved for the first time by C?H bond activation. This catalytic redox-neutral process resulted in the synthesis of 1,4-dicarbonyl compounds. Notably, allylic alcohols bearing tetrasubstituted olefins can also be transformed into their corresponding carbonyl compounds. Density functional theory calculations show that the carbonyl group at the γ-position of allylic alcohols are beneficial to the formation of their corresponding allylic alcohol radicals with high vertical electron affinity, which contributes to the completion of the photoredox catalytic cycle.
Guo, Kai,Huang, Jun,Li, Anding,Li, Yuanhe,Yang, Zhen,Zhang, Zhongchao
p. 11660 - 11668
(2020/05/25)

Transition Metal-Free Alkyne-Aldehyde Reductive C?C Coupling trough Cascade Borylation/Olefin Isomerization
A direct approach to γ-keto esters through cascade alkyne-aldehyde reductive C?C coupling of propargyl esters and aromatic aldehydes under transition-metal-free (TM-free) fashion was developed. Compared with multistep processes, this procedure provides a
Khan, Imran,Luo, Zhibin,Xu, Yin,Xie, Jimin,Zhu, Weihua,Liu, Bin
(2020/05/04)

An expeditious entry to rare tetrahydroimidazo[1,5-c]pyrrolo[1,2-a]pyrimidin-7(8H)-ones: A single-step gateway synthesis of glochidine congeners
A single-step gateway synthesis of glochidine and its congeners that possess the rare uncommon tetrahydroimidazo[1,5-c]pyrrolo[1,2-a]pyrimidine core was developed employing histamine and readily available γ-ketoesters. Key features of the developed reaction involve tandem three C–N bonds formation and concomitant annulation of two rings in one pot to access this unique and complex tricyclic structure. Exploration of the unknown bioactivity of these compounds revealed that they elicit antiproliferative activity comparable to the anticancer drug imatinib against 6 cancer cell lines.
Seo, Jeong Moo,Hassan, Ahmed H.E.,Lee, Yong Sup
supporting information

(2019/11/26)

Synthesis of Novel C 2-Symmetric Sulfur-Based Catalysts: Asymmetric Formation of Halo- and Seleno-Functionalized Normal- and Medium-Sized Rings
The synthesis of novel, highly functionalized, C 2 -symmetric sulfur-based catalysts is developed and their catalytic applications are explored in asymmetric bromo-, iodo- and seleno-functionalizations of alkenoic acids. This protocol provides
Jana, Sadhan,Kumar, Sangit,Rathore, Vandana,Verma, Ajay
supporting information
p. 1667 - 1672
(2019/08/28)

Copper-Catalyzed Decarboxylative Oxyalkylation of Alkynyl Carboxylic Acids: Synthesis of ?-Diketones and ?-Ketonitriles
A novel copper-catalyzed decarboxylative oxyalkylation of alkynyl carboxylic acids with ketones and alkylnitriles via direct C(sp3)-H bond functionalization to construct new C-C bonds and C-O double bonds was developed. This transformation is featured by wide functional group compatibility and the use of readily available reagents, thus affording a general approach to ?-diketones and ?-ketonitriles. A possible mechanism is proposed.
Li, Yi,Shang, Jia-Qi,Wang, Xiang-Xiang,Xia, Wen-Jin,Yang, Tao,Xin, Yangchun,Li, Ya-Min
supporting information
p. 2227 - 2230
(2019/03/26)

O-Heterocycles from Unsaturated Carbonyls and Dimethoxycarbene
The (4+1)-annulation of dimethoxycarbene with readily accessible α,β-unsaturated carbonyls gives cyclic orthoesters, which can then be converted in just a few steps to other O-heterocycles, including methoxyfurans, furanones, and furans.
Croisetière, Jean-Philippe,Spino, Claude
p. 5609 - 5618
(2018/05/08)

Copper-catalyzed vinylogous aerobic oxidation of unsaturated compounds with air
A mild and operationally simple copper-catalyzed vinylogous aerobic oxidation of β,γ- and α,β-unsaturated esters is described. This method features good yields, broad substrate scope, excellent chemo- and regioselectivity, and good functional group tolerance. This method is additionally capable of oxidizing β,γ- and α,β-unsaturated aldehydes, ketones, amides, nitriles, and sulfones. Furthermore, the present catalytic system is suitable for bisvinylogous and trisvinylogous oxidation. Tetramethylguanidine (TMG) was found to be crucial in its role as a base, but we also speculate that it serves as a ligand to copper(II) triflate to produce the active copper(II) catalyst. Mechanistic experiments conducted suggest a plausible reaction pathway via an allylcopper(II) species. Finally, the breadth of scope and power of this methodology are demonstrated through its application to complex natural product substrates.
Zhang, Hai-Jun,Schuppe, Alexander W.,Pan, Shi-Tao,Chen, Jin-Xiang,Wang, Bo-Ran,Newhouse, Timothy R.,Yin, Liang
supporting information
p. 5300 - 5310
(2018/04/24)

Guiding a divergent reaction by photochemical control: Bichromatic selective access to levulinates and butenolides
Allylic and acrylic substrates may be efficiently transformed by a sequential bichromatic photochemical process into derivatives of levulinates or butenolides with high selectivity when phenanthrene is used as a regulator. Thus, UV-A photoinduced cross-metathesis (CM) couples the acrylic and allylic counterparts and subsequent UV-C irradiation initiates E-Z isomerization of the carbon-carbon double bond, followed by one of two competing processes; namely, cyclization by transesterification or a 1,5-H shift and tautomerization. Quantum chemical calculations demonstrate that intermediates are strongly blue-shifted for the cyclization while red-shifted for the 1,5-H shift reaction. Hence, delaying the double bond migration by employing UV-C absorbing phenanthrene, results in a selective novel divergent all-photochemical pathway for the synthesis of fundamental structural motifs of ubiquitous natural products.
Sutar, Revannath L.,Sen, Saumik,Eivgi, Or,Segalovich, Gal,Schapiro, Igor,Reany, Ofer,Lemcoff, N. Gabriel
p. 1368 - 1374
(2018/02/09)

Thieme Chemistry Journals Awardees - Where Are They Now? Bis(2-pyridyl)amides as Readily Cleavable Amides under Catalytic, Neutral, and Room-Temperature Conditions
Mild solvolytic cleavage of bis(2-pyridyl)amide under neutral and room-temperature conditions is described. The inherently stable amide was readily activated by catalytic amounts of metal cations to react with alcohols. Based on X-ray crystallographic analysis, the primary driving force was considered to be amide distortion induced by the metal coordination of two pyridyl groups in a bidentate fashion without affecting the amide functionality. The compatibility of the acid/base-sensitive functionalities and the absence of racemization during solvolysis highlight the mildness of the present protocol.
Adachi, Shinya,Kumagai, Naoya,Shibasaki, Masakatsu
supporting information
p. 301 - 305
(2018/02/10)

Visible-Light-Promoted Synthesis of 1,4-Dicarbonyl Compounds via Conjugate Addition of Aroyl Chlorides
A facile visible-light photocatalytic conjugate addition to prepare 1,4-dicarbonyl compounds has been developed by employing readily available aroyl chlorides as aryl radical sources. This operationally simple method shows a broad scope with regard to both aroyl chlorides and Michael acceptors. As a result, a variety of 1,4-diketones were efficiently synthesized in moderate to good yields.
Wang, Chao-Ming,Song, Dan,Xia, Peng-Ju,Wang, Jing,Xiang, Hao-Yue,Yang, Hua
supporting information
p. 271 - 274
(2018/01/27)

Photoredox-Catalyzed Hydroacylation of Olefins Employing Carboxylic Acids and Hydrosilanes
A hydroacylation reaction of alkenes has been achieved employing readily available carboxylic acids as the acyl source and hydrosilanes as a hydrogen source via photoredox catalysis. The combination of both single electron transfer and hydrogen atom transfer steps has dramatically expanded new applications of carboxylic acids in organic synthesis. The protocol also features extremely mild conditions, broad substrate scope, and good functional group tolerance, affording a novel and convenient approach to hydroacylation of alkenes.
Zhang, Muliang,Ruzi, Rehanguli,Xi, Junwei,Li, Nan,Wu, Zhongkai,Li, Weipeng,Yu, Shouyun,Zhu, Chengjian
supporting information
p. 3430 - 3433
(2017/07/15)

Mg(OMe)2 promoted allylic isomerization of γ-hydroxy-α,β-alkenoic esters to synthesize γ-ketone esters
This work concerns the Mg(OMe)2 promoted allylic isomerization of γ-hydroxy-α,β-alkenoic esters with TMEDA as an additive. The isomerization proceeded under mild conditions and afforded γ-keto esters in high yield (up to 96%) within 2 h. Both (Z)- and (E)-γ-hydroxy-α,β-alkenoic esters were tolerated under the reaction conditions. This transformation involves the in situ formation of a dienolate intermediate from the easily accessible γ-hydroxy-α,β-alkenoic ester. The in situ generated dienolate can react with benzaldehyde and undergo a practical, useful tandem allylic isomerization-Aldol reaction to afford more functionalized compounds.
Lai, Luhao,Li, A-Ni,Zhou, Jiawei,Guo, Yarong,Lin, Li,Chen, Wei,Wang, Rui
p. 2185 - 2190
(2017/03/17)

Cyclic ether synthesis from diols using trimethyl phosphate
Cyclic ethers have been effectively synthesized via the intramolecular cyclization of diols using trimethyl phosphate and NaH. The present cyclization could proceed at room temperature to produce 5-7 membered cyclic ethers in good to excellent yields. Substrates possessing a chiral secondary hydroxy group were transformed into the corresponding chiral cyclic ethers along with the retention of their stereochemistries.
Asai, Shota,Kato, Maho,Monguchi, Yasunari,Sajiki, Hironao,Sawama, Yoshinari
supporting information
p. 4787 - 4790
(2017/07/06)

Nucleophile-Assisted Alkene Activation: Olefins Alone Are Often Incompetent
Emerging work on organocatalytic enantioselective halocyclizations naturally draws on conditions where both new bonds must be formed under delicate control, the reaction regime where the concerted nature of the AdE3 mechanism is of greatest importance. Without assistance, many simple alkene substrates react slowly or not at all with conventional halenium donors under synthetically relevant reaction conditions. As demonstrated earlier by Shilov, Cambie, Williams, Fahey, and others, alkenes can undergo a concerted AdE3-type reaction via nucleophile participation, which sets the configuration of the newly created stereocenters at both ends in one step. Herein, we explore the modulation of alkene reactivity and halocyclization rates by nucleophile proximity and basicity, through detailed analyses of starting material spectroscopy, addition stereopreferences, isotope effects, and nucleophile-alkene interactions, all obtained in a context directly relevant to synthesis reaction conditions. The findings build on the prior work by highlighting the reactivity spectrum of halocyclizations from stepwise to concerted, and suggest strategies for design of new reactions. Alkene reactivity is seen to span the range from the often overgeneralized "sophomore textbook" image of stepwise electrophilic attack on the alkene and subsequent nucleophilic bond formation, to the nucleophile-assisted alkene activation (NAAA) cases where electron donation from the nucleophilic addition partner activates the alkene for electrophilic attack. By highlighting the factors that control reactivity across this range, this study suggests opportunities to explain and control stereo-, regio-, and organocatalytic chemistry in this important class of alkene additions.
Ashtekar, Kumar Dilip,Vetticatt, Mathew,Yousefi, Roozbeh,Jackson, James E.,Borhan, Babak
supporting information
p. 8114 - 8119
(2016/07/16)

Decarboxylative 1,4-Addition of α-Oxocarboxylic Acids with Michael Acceptors Enabled by Photoredox Catalysis
Enabled by iridium photoredox catalysis, 2-oxo-2-(hetero)arylacetic acids were decarboxylatively added to various Michael acceptors including α,β-unsaturated ester, ketone, amide, aldehyde, nitrile, and sulfone at room temperature. The reaction presents a new type of acyl Michael addition using stable and easily accessible carboxylic acid to formally generate acyl anion through photoredox-catalyzed radical decarboxylation.
Wang, Guang-Zu,Shang, Rui,Cheng, Wan-Min,Fu, Yao
supporting information
p. 4830 - 4833
(2015/10/12)

Br?nsted Acid-Catalyzed Intramolecular Nucleophilic Substitution of the Hydroxyl Group in Stereogenic Alcohols with Chirality Transfer
The hydroxyl group of enantioenriched benzyl, propargyl, allyl, and alkyl alcohols has been intramolecularly displaced by uncharged O-, N-, and S-centered nucleophiles to yield enantioenriched tetrahydrofuran, pyrrolidine, and tetrahydrothiophene derivatives with phosphinic acid catalysis. The five-membered heterocyclic products are generated in good to excellent yields, with high degree of chirality transfer, and water as the only side-product. Racemization experiments show that phosphinic acid does not promote SN1 reactivity. Density functional theory calculations corroborate a reaction pathway where the phosphinic acid operates as a bifunctional catalyst in the intramolecular substitution reaction. In this mechanism, the acidic proton of the phosphinic acid protonates the hydroxyl group, enhancing the leaving group ability. Simultaneously, the oxo group of phosphinic acid operates as a base abstracting the nucleophilic proton and thus enhancing the nucleophilicity. This reaction will open up new atom efficient techniques that enable alcohols to be used as nucleofuges in substitution reactions in the future.
Bunrit, Anon,Dahlstrand, Christian,Olsson, Sandra K.,Srifa, Pemikar,Huang, Genping,Orthaber, Andreas,Sj?berg, Per J. R.,Biswas, Srijit,Himo, Fahmi,Samec, Joseph S. M.
supporting information
p. 4646 - 4649
(2015/04/27)

Remote activation of the nucleophilicity of isatin
The concept of the remote activation of reactivity was first applied in asymmetric organocatalysis. An isatin 3-phenylimine derivative acts as a donor in the thiourea catalyzed asymmetric addition to unsaturated 1,4-ketoesters, affording aza-Michael adducts in high enantiomeric purity and yield.
Zari, Sergei,Kudrjashova, Marina,Pehk, Tonis,Lopp, Margus,Kanger, Tonis
supporting information
p. 1740 - 1743
(2014/04/17)

Enantioselective synthesis of tetrahydrofuran derivatives by sequential henry reaction and iodocyclization of γ,δ-unsaturated alcohols
A sequential one-pot Cu-catalyzed asymmetric Henry reaction and iodocyclization is disclosed. The transformation provides efficient access to biologically and synthetically useful 2,2,5-trisubstituted tetrahydrofuran derivatives. The combination of Cu(OAc)2·H2O with a novel chiral sulfoxide-Schiff base hybrid ligand under mild reaction conditions tolerates a wide range of 4-substituted γ,δ-unsaturated aldehydes, and the subsequent iodocyclization furnishes the corresponding products in generally high yields with excellent enantioselectivities. The products can be easily converted into amines with excellent diastereo- and enantioselectivities.
Chen, Li-Yan,Chen, Jia-Rong,Cheng, Hong-Gang,Lu, Liang-Qiu,Xiao, Wen-Jing
supporting information
p. 4714 - 4719
(2014/08/05)

Methods for the synthesis of chiral sulfur heterocycles and their application in the asymmetric Baylis-Hillman reactions
Enantiomerically pure (2S,6S)-2,6-diphenyltetrahydro-2H-thiopyran, (2S)-2-phenyltetrahydro thiophene, and (2S)-2-phenyltetrahydro-2H-thiopyran were prepared in 70-72% yields and with 86-99% ee via cyclization of the corresponding dimesylate in an SN2 cyclization reaction using sodium sulfide nonahydrate. The results on the application of various chiral sulfides in asymmetric Baylis-Hillman reactions are also described.
Periasamy, Mariappan,Gurubrahamam, Ramani,Muthukumaragopal, Gopal P.
p. 568 - 574
(2013/06/27)

Cross metathesis of allyl alcohols: How to suppress and how to promote double bond isomerization
Under standard conditions the cross metathesis of allyl alcohols and methyl acrylate is accompanied by the formation of ketones, resulting from uncontrolled and undesired double bond isomerization. By conducting the CM in the presence of phenol, the catalyst loading and the reaction time required for quantiative conversion can be reduced, and isomerization can be suppressed. On the other hand, consecutive isomerization can be deliberately promoted by evaporating excess methyl acrylate after completing cross metathesis and by adding a base or silane as chemical triggers.
Schmidt, Bernd,Hauke, Sylvia
p. 4194 - 4206
(2013/07/05)

Asymmetric iodolactonization utilizing chiral squaramides
Asymmetric iodolactonization of γ- and δ-unsaturated carboxylic acids has been explored in the presence of six different chiral organocatalysts 5-8. The catalyst 6b was found to facilitate the cyclization of 5-arylhex-5-enoic acids 1 to the corresponding
Tungen, Jorn E.,Nolsoe, Jens M. J.,Hansen, Trond V.
supporting information
p. 5884 - 5887
(2013/02/23)

Modification and optimization of the bis-picolylamide-based relay protection for carboxylic acids to be cleaved by unusual complexation with Cu2+ salts
A simple modification of our recently published protection scheme for carboxylic acids as amides resulted in a new protecting group with significantly improved properties. It requires shorter reaction times for deprotection and allows us to replace Cu(OTf)2 by CuCl2, indicating at the same time the importance of the nature of the anion of the Cu2+ source. Since the new scheme fulfills all criteria required for an ideal protection group it should find widespread application in synthetic organic chemistry.
Mundinger, Stephan,Jakob, Uwe,Bichovski, Plamen,Bannwarth, Willi
p. 8968 - 8979,12
(2012/12/11)

Direct and selective benzylic oxidation of alkylarenes via C-H abstraction using alkali metal bromides
A direct benzylic oxidation of alkylarenes via C-H bond abstraction was developed using alkali metal bromides and oxidants under mild conditions. This reaction proceeded with excellent selectivity by thermal oxidation or photooxidation to provide a broad range of carbonyl compounds containing electron-deficient aryl carbonyl compounds in high yields.
Moriyama, Katsuhiko,Takemura, Misato,Togo, Hideo
supporting information; experimental part
p. 2414 - 2417
(2012/06/18)

Inter- and intramolecular hydroacylation of alkenes employing a bifunctional catalyst system
Based on a conceptually innovative bifunctional P,N ligand, an efficient protocol for the rhodium-catalyzed inter- and intramolecular hydroacylation of alkenes has been developed.
Vautravers, Nicolas R.,Regent, Damien D.,Breit, Bernhard
supporting information; experimental part
p. 6635 - 6637
(2011/06/27)

Nucleophilic ring-opening of epoxide and aziridine acetates for the stereodivergent synthesis of β-Hydroxy and β-Amino γ-Lactams
A highly regio- and stereoselective synthesis of novel β,γ- disubstituted γ-lactams with either an anti or syn relative configuration was developed from readily available epoxide and aziridine acetates. The key steps include the regio- and diastereocontrolled nucleophilic ring-opening of these three-membered heterocycles followed by mild reductive cyclization of the γ-azido ester intermediate. The method was also extended to an asymmetric synthesis of (4R,5S)-4-hydroxy-5-phenylpyrrolidin-2-one from a chiral epoxide acetate. The main features of this versatile synthesis of functionalized γ-lactams include the involvement of inexpensive reagents and mild conditions together with high chemical efficiency.
Bisol, Tula B.,Bortoluzzi, Adailton J.,Sa, Marcus M.
scheme or table
p. 948 - 962
(2011/04/12)

Chelating carboxylic acid amides as robust relay protecting groups of carboxylic acids and their cleavage under mild conditions
Free choice: Carboxamides of bispicolylamine are alternative protecting groups for carboxylic acids (see scheme). As a consequence of their straightforward applicability, their high chemical stability towards a broad range of conditions, and their selective cleavage under mild conditions to give either carboxylic acids or their methyl esters, this new protection method should find widespread application in the realm of organic synthesis. Copyright
Broehmer, Manuel C.,Mundinger, Stephan,Braese, Stefan,Bannwarth, Willi
supporting information; experimental part
p. 6175 - 6177
(2011/08/03)

Effect of carbon chain length in the substituent of PCBM-like molecules on their photovoltaic properties
A series of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM)-like fullerene derivatives with the butyl chain in PCBM changing from 3 to 7 carbon atoms, respectively (F1-F5), are designed and synthesized to investigate the relationship between
Zhao, Guangjin,He, Youjun,Xu, Zheng,Hou, Jianhui,Zhang, Maojie,Min, Jie,Chen, Hsiang-Yu,Ye, Mingfu,Hong, Ziruo,Yang,Li, Yongfang
experimental part
p. 1480 - 1487
(2011/12/02)

Unified oxidation protocol for the synthesis of carbonyl compounds using a manganese catalyst
We have developed a unified protocol for the oxidation of ethers, benzylic compounds, and alcohols to carbonyl compounds. The protocol uses catalytic amounts of manganese(II) chloride tetrahydrate and tri(t-butyl)-2,2':6',2Prime;- terpyridine in combination with a stoichiometric amount of either m-chloroperbenzoic acid (MCPBA) or potassium hydrogen peroxysulfate (KHSO 5). A reagent system consisting of the Mn catalyst and MCPBA permitted the chemoselective sp3 C-H oxidation of alkyl ethers and benzylic compounds to generate the corresponding ketones. Alternatively, the water-soluble inorganic salt KHSO5 in combination with the Mn catalyst was used to oxidize alcohols to ketones or carboxylic acids. Importantly, the Mn catalyst/KHSO5 system eliminates technical difficulties associated with the isolation of carboxylic acid products. All the oxidations presented in this feature article proceed at sup-ambient temperature in an aerobic atmosphere, and can therefore be used in practical syntheses of complex organic molecules. Georg Thieme Verlag Stuttgart · New York.
Kamijo, Shin,Amaoka, Yuuki,Inoue, Masayuki
experimental part
p. 2475 - 2489
(2010/09/06)

Carbamoylation of aryl halides by molybdenum or tungsten carbonyl amine complexes
When aryl halide is treated with molybdenum carbonyl amine complex in the presence of base, carbamoylation proceeds to give amide in good yield. The proposed mechanism involves oxidative addition of aryl halide to molybdenum(0) complex, migratory insertio
Ren, Wei,Yamane, Motoki
supporting information; experimental part
p. 3017 - 3020
(2010/07/05)

Design and synthesis of novel bis-oximinoalkanoic acids as potent PPARα agonists
Bis-oximinoalkanoic acid derivatives were designed and synthesized to aid in the characterization of selective PPARα agonists by replacing the oxazole ring with flexible oximino group in the lipophilic tail part of a previously reported compound 3. Selected compounds 9d and 9m showed excellent potency and high selectivity towards PPARα in vitro. These compounds found effective in reducing serum triglycerides (TG) in vivo.
Pingali, Harikishore,Jain, Mukul,Shah, Shailesh,Zaware, Pandurang,Makadia, Pankaj,Pola, Suresh,Thube, Baban,Patel, Darshit,Patil, Pravin,Priyadarshini, Priyanka,Suthar, Dinesh,Shah, Maanan,Giri, Suresh,Patel, Pankaj
body text
p. 1156 - 1161
(2010/06/15)

Copper(0)-induced aminocyclopropanation of olefins via deselenation of N,N-disubstituted aromatic selenoamides
Upon heating of a mixture of N,N-disubstituted aromatic selenoamides and several electron-deficient olefins in the presence of copper(0) powder, a novel deselenative cyclopropanation takes place to afford the corresponding aminocyclopropanes in good yields. When acrylonitrile is employed as an electron-deficient olefin, the aminocyclopentanation occurs in preference to the aminocyclopropanation by prolonging the reaction time. The obtained aminocyclopropane derivatives can be converted to the corresponding 1,4-dicarbonyl compounds upon treatment with 2 N HCl.
Mitamura, Takenori,Nomoto, Akihiro,Sonoda, Motohiro,Ogawa, Akiya
experimental part
p. 9983 - 9988
(2009/04/03)

Synthesis and investigation of fullerene-based acceptor materials
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Mayorova, Julia Yu.,Nikitenko, Sergei L.,Troshin, Pavel A.,Peregudova, Svetlana M.,Peregudov, Alexander S.,Kaplunov, Mikhail G.,Lyubovskaya, Rimma N.
p. 175 - 177
(2008/02/03)

One-pot synthesis of oxo acid derivatives by RhI-catalyzed chelation-assisted hydroacylation
Various oxo acid derivatives were obtained directly from the reaction of aliphatic and aromatic aldehydes with ω-alkenoic acid derivatives in the presence of rhodium(I) complexes and 2-amino-3-picoline. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
Jo, Eun-Ae,Jun, Chul-Ho
p. 2504 - 2507
(2007/10/03)

An expeditious synthesis of methyl 5-(2-amino 4-arylthiazolyl) acetates using microwave irradiation
2,4,5-Trisubstituted thiazole derivatives can be prepared conveniently by condensation of methyl 3-bromo-3-aroyl propionates with thiourea and (un)substituted phenyl thiourea under microwave irradiation in good yields. The structures of the newly synthesized compounds are characterized by spectral data and elemental analysis.
Attimarad, Mahesh,Mohan
p. 1276 - 1279
(2008/09/21)

Electrochemical generation and catalytic use of selenium electrophiles
The generation and use of selenium electrophiles in catalytic, electrochemically driven selenenylation-elimination sequences is described. Georg Thieme Verlag Stuttgart.
Niyomura, Osamu,Cox, Matthew,Wirth, Thomas
p. 251 - 254
(2007/10/03)

Highly selective regeneration of carbonyl compounds from their oximes and semicarbazones in aqueous medium
Chemoselective regeneration of aryl alkyl ketone, α-tetralone, and cycloalkanone by hydrolysis of their oximes and semicarbazones has been accomplished using aqueous phosphoric acid without involvement of any organic cosolvent in the reaction medium, where the similar derivatives of aryl aldehyde, diaryl ketone, aliphatic acyclic aldehyde and ketone remain mostly inert. Copyright Taylor & Francis, Inc.
Bhar, Sanjay,Guha, Sharmistha
p. 1183 - 1188
(2007/10/03)

Stetter reaction in room temperature ionic liquids and application to the synthesis of haloperidol
Imidazolium-type room temperature ionic liquids (RTILs) have been used for the Stetter reaction, affording the desired 1,4-dicarbonyl compounds in good yields. Thiazolium salts and Et3N are efficient catalysts for this reaction performed in ionic liquid. The possibility to recycle and reuse the solvent has been demonstrated, although it was not possible to recycle the thiazolium catalyst. This method was used in the total synthesis of haloperidol.
Anjaiah, Siddam,Chandrasekhar, Srivari,Gree, Rene
p. 1329 - 1334
(2007/10/03)

Methods of using norfluoxetine
The invention encompasses methods of using racemic and enantiomerically pure norfluoxetine, as well as pharmaceutical compositions, pharmaceutical unit dosage forms, and kits comprising racemic and enantiomerically pure norfluoxetine. In particular, the i
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(2008/06/13)

Stereoselective synthesis of trans-4,5-disubstituted oxazolidin-2-ones by intramolecular conjugate addition of N-p-toluenesulfonyl carbamates
p-Toluenesulfonyl carbamates (2a-d) were prepared starting from allylic alcohols (3), in which the double bond is conjugated with an electron withdrawing group. In the presence of a catalytic amount of DBU, an intramolecular cyclisation occurred, leading
Ciclosi, Marco,Fava, Cristiana,Galeazzi, Roberta,Orena, Mario,Sepúlveda-Arques, José,González-Rosende, Maria Eugenia
p. 1173 - 1183
(2007/10/03)

Acylation of α-(N-carbamoyl)alkylcuprates and alkyl- or aryl(halo)cuprates
α-(N-Carbamoyl)alkylcuprates [R2CuLi·LiX or RCuXLi (X=CN, Cl)] when prepared from THF soluble CuX·2LiCl (X=Cl, CN) undergo a reliable and generally high yield reaction with aroyl, alkanoyl, and alkenoyl chlorides to provide a rapid and efficient synthesis of α-carbamoyl ketones. Cuprates prepared from acyclic, cyclic, and a functionalized carbamate can be utilized. Although yields are a function of cuprate reagent and substrate structure, nearly quantitative yields can be obtained with reagents generated from 2RLi+CuCN·2LiCl. The use of reagents generated from CuCl·2LiCl are more efficient in the α-(N-carbamoyl)alkyl ligand, although yields are slightly lower. Acylation of alkyl(chloro)cuprates generated from one equivalent of CuCl·2LiCl and organolithium or Grignard reagents provides an efficient and high yield procedure for ketone synthesis.
Dieter, R. Karl,Sharma, Ram R.,Yu, Huayun,Gore, Vinayak K.
p. 1083 - 1094
(2007/10/03)

Formation of γ-keto esters from β-keto esters: Methyl 5,5-dimethyl-4-oxohexanoate: [Hexanoic acid, 5,5-dimethyl-4-oxo-, methyl ester]
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Ronsheim, Matthew D.,Hilgenkamp, Ramona K.,Zercher, Charles K.,Denmark, Scott E.,Beutner, Gregory L.
p. 146 - 146
(2017/09/08)

Palladium-catalyzed synthesis of aryl ketones from boronic acids and carboxylic acids activated in situ by pivalic anhydride
A new palladium-catalyzed cross-coupling reaction between arylboronic acids and mixed anhydrides, generated in situ from carboxylic acids and pivalic anhydride, is presented. Optimization of the new catalyst and the reaction conditions led to the development of a convenient one-pot ketone synthesis directly from carboxylic and boronic acids in the presence of different (phosphane)palladium complexes in wet THF at 60 °C. Systematic studies were performed to elucidate the reaction mechanism of this transformation. The scope and the limitations of the new process are demonstrated by the synthesis of 33 functionalized ketones. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
Goossen, Lukas J.,Ghosh, Keya
p. 3254 - 3267
(2007/10/03)