cas 447-31-4, DESYL CHLORIDE | Articles data

Articles about 447-31-4Total 43 be found

Article title
Article abstract
Author
Journal number and time
Download

Synthesis and evaluation of novel diphenylthiazole derivatives as potential anti-inflammatory agents
In the presented study, we synthesized a novel series of 18 diphenylthiazole derivatives and tested their anti-inflammatory properties. They showed significant anti-inflammatory properties in inflamed mice paws animal model. Docking-based analysis suggested that they act as COX enzyme inhibitors. The most potent compound 9e is significantly more active in reducing inflamed animal paws compared to diclofenac. Accordingly, we believe these compounds are good leads for further development into potent anti-inflammatory drugs.
Abdelazeem, Ahmed H.,Habash, Maha,Maghrabi, Ibrahim A.,Taha, Mutasem O.
p. 3681 - 3695
(2015)
Read Online

Design, Synthesis, and Anti-Inflammatory Evaluation of Novel Diphenylthiazole-Thiazolidinone Hybrids
A series of diphenylthiazole-thiazolidinone hybrids was synthesized and evaluated in vitro and in vivo as anti-inflammatory/analgesic agents. The inhibition of cyclooxygenase (COX) enzymes was suggested as a molecular mechanism for the hybrids to exert their anti-inflammatory action. Of these compounds, 13b, 14, and 15b showed the most potent COX inhibitory activity with IC50 values between 2.03 and 12.27 μM, but with different selectivity profiles. All compounds were further evaluated in vivo for their anti-inflammatory/analgesic activities using three animal models. Interestingly, the results of the COX assay were in agreement with those of in vivo assays where the most potent COX inhibitors, 13b, 14, and 15b, exhibited the highest anti-inflammatory/analgesic activities compared to diclofenac. On the contrary, compounds 11 and 12 were the least potent ligands in vitro and in vivo as well.
Abdelazeem, Ahmed H.,Salama, Samir A.,Maghrabi, Ibrahim A.
p. 518 - 530
(2015)
Read Online

Design, synthesis and biological evaluation of novel diphenylthiazole-based cyclooxygenase inhibitors as potential anticancer agents
Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most widely used medications as analgesics and antipyretics. Currently, there is a growing interest in their antitumor activity and their ability to reduce the risk and mortality of several cancers. While several studies revealed the ability of NSAIDs to induce apoptosis and inhibit angiogenesis in cancer cells, their exact anticancer mechanism is not fully understood. However, both cyclooxygenase (COX)-dependent and -independent pathways were reported to have a role. In an attempt to develop new anticancer agents, a series of diphenylthiazole substituted thiazolidinone derivatives was synthesized and evaluated for their anticancer activity against a panel of cancer cell lines. Additionally, the inhibitory activity of the synthesized derivatives against COX enzymes was investigated as a potential mechanism for the anticancer activity. Cytotoxicity assay results showed that compounds 15b and 16b were the most potent anticancer agents with half maximal inhibitory concentrations (IC50) between 8.88 and 19.25?μM against five different human cancer cell lines. Interestingly, COX inhibition assay results were in agreement with that of the cytotoxicity assays where the most potent anticancer compounds showed good COX-2 inhibition comparable to that of celecoxib. Further support to our results were gained by the docking studies which suggested the ability of compound 15b to bind into COX-2 enzyme with low energy scores. Collectively, these results demonstrated the promising activity of the newly designed compounds as leads for subsequent development into potential anticancer agents.
Abdelazeem, Ahmed H.,Gouda, Ahmed M.,Omar, Hany A.,Tolba, Mai F.
p. 132 - 141
(2014)
Read Online

Access to α,α-dihaloacetophenones through anodic C[dbnd]C bond cleavage in enaminones
We have developed a method to synthesize α,α-dihaloketones under electrochemical conditions. In this reaction, the Cl- or Br- is oxidized to Cl2 or Br2 at the anode, which undergoes two-step addition reactions with the N,N-dimethyl enaminone, and finally breaks C[dbnd]C of the N,N-dimethyl enaminone to generate α,α-dihaloketones. The electrosynthesis reaction can be conveniently carried out in an undivided electrolytic cell at room temperature. In addition, various functional groups are compatible with this green protocol which can be applied simultaneously to the gram scale without significantly lower yield.
Bu, Jiping,Huang, Zijun,Li, Shaoke,Ma, Xiantao,Wu, Kairui,Yang, Jiusi,Yu, Renjie,Zhang, Zhenlei
supporting information

(2021/12/20)

Thiourea-Mediated Halogenation of Alcohols
The halogenation of alcohols under mild conditions expedited by the presence of substoichiometric amounts of thiourea additives is presented. The amount of thiourea added dictates the pathway of the reaction, which may diverge from the desired halogenation reaction toward oxidation of the alcohol, in the absence of thiourea, or toward starting material recovery when excess thiourea is used. Both bromination and chlorination were highly efficient for primary, secondary, tertiary, and benzyl alcohols and tolerate a broad range of functional groups. Detailed electron paramagnetic resonance (EPR) studies, isotopic labeling, and other control experiments suggest a radical-based mechanism. The fact that the reaction is carried out at ambient conditions, uses ubiquitous and inexpensive reagents, boasts a wide scope, and can be made highly atom economic, makes this new methodology a very appealing option for this archetypical organic reaction.
Mohite, Amar R.,Phatake, Ravindra S.,Dubey, Pooja,Agbaria, Mohamed,Shames, Alexander I.,Lemcoff, N. Gabriel,Reany, Ofer
p. 12901 - 12911
(2020/11/26)

High yield preparation method of selexipag intermediate compound under middle conditions
The invention relates to a high yield preparation method of a selexipag intermediate compound under middle conditions. According to the method, styracitol and halogen acid carry out halogenation reactions, and the reaction product and N-aminoacetyl-N-isopropyl n-butanol carry out condensation, ammoxidation, and ring forming reactions to obtain 2-(N-isopropyl-N-4-hydroxylbutyl)amino-5,6-diphenylpyrazine. The compound can be used to prepare selexipag. The raw materials are cheap and easily available, the operation is simple, convenient and safe, the reaction selectivity is good, the yield and purity are high, and the cost is low.
-
Paragraph 0057-0058

(2019/03/15)

The Mn-catalyzed paired electrochemical facile oxychlorination of styrenes: Via the oxygen reduction reaction
Reported herein is the electrochemical engendering of chlorine radicals by a manganese catalyst with a controllable pattern, and inexpensive MgCl2 as the chlorine source. In combination with the oxygen reduction reaction, chloroacetophenones were synthesized with abundant styrene as the feedstock in good to excellent yields.
Tian, Siyu,Jia, Xiaofei,Wang, Ling,Li, Baoying,Liu, Siyuan,Ma, Li,Gao, Wei,Wei, Yingqin,Chen, Jianbin
supporting information
p. 12104 - 12107
(2019/10/14)

CV-driven Optimization: Cobalt-Catalyzed Electrochemical Expedient Oxychlorination of Alkenes via ORR
Instead of screening reaction conditions by yield-based chemical trial-and-error, potential-based cyclic voltammetry was alternatively employed for optimization of electrochemical oxychlorination of alkenes. With this unconventional screening method, the catalyst system including catalysts, molar ratio of chloride sources and solvents were identified in a rational, time- and energy-efficient manner. The optimal catalytic system in combination with oxygen reduction reaction enabled broad substrate scopes for the desired transformation by taking advantages of persistent radical effect. UV-vis and CV titration experiments confirmed the in-situ formed catalytic species [CoCl5]. Moreover, cyclic voltammetry was applied to obtain mechanistic insights in our reaction system. (Figure presented.).
Tian, Siyu,Lv, Shide,Jia, Xiaofei,Ma, Li,Li, Baoying,Zhang, Guofeng,Gao, Wei,Wei, Yingqin,Chen, Jianbin
supporting information
p. 5626 - 5633
(2019/11/22)

Coupling of Sulfoxonium Ylides with Arynes: A Direct Synthesis of Pro-Chiral Aryl Ketosulfoxonium Ylides and Its Application in the Preparation of α-Aryl Ketones
A general, mild, and versatile synthesis of the challenging α-aryl-β-ketosulfoxonium ylides has been developed for the first time, substituting traditional methods starting from diazo compounds. The arylation of easily accessible β-ketosulfoxonium ylides using aryne chemistry allowed the preparation of a large scope of the pro-chiral ylides in very good yields (40 examples; up to 85%). As applications, these ylides were smoothly converted into α-aryl ketones after desulfurization in good yields (up to 98%) as well as in other important derivatives.
Talero, Alexánder Garay,Martins, Bruna Sim?es,Burtoloso, Antonio C. B.
p. 7206 - 7211
(2018/11/23)

Design, synthesis and analgesic/anti-inflammatory evaluation of novel diarylthiazole and diarylimidazole derivatives towards selective COX-1 inhibitors with better gastric profile
The inhibition of gastric cyclooxygenase 1 (COX-1) enzyme was believed to be the major cause of non-steroidal anti-inflammatory drugs (NSAIDs)-induced gastric ulcer. Recent studies disproved this belief and showed that the gastric tissues vulnerability is not solely connected to COX-1 inhibition. This work aimed at exploring and rationalizing the differential analgesic and anti-inflammatory activities of novel selective COX-1 inhibitors with improved gastric profile. Two novel series of 4,5-diarylthiazole and diarylimidazole were designed, synthesized in analogy to selective COX-1 inhibitors (mofezolac and FR122047) which lack gastric damaging effects. The new compounds were evaluated in vitro for their COXs inhibitory activity and in vivo for their anti-inflammatory and analgesic potentials. Four compounds; diphenylthiazole glycine derivatives (15a, 15b) and diphenylimidazolo acetic acid derivatives (19a, 19b), which possess carboxylic acid group exhibited significant activity and selectivity against COX-1 over COX-2. Of these compounds, (4,5-bis(4-methoxyphenyl)thiazol-2-yl)glycine 15b was the most potent compound against COX-1 with an inhibitory half maximal concentration (IC50) of 0.32 μM and a selectivity index (COX-2 IC50/COX-1 IC50) of 28.84. Furthermore, an ulcerogenicity study was performed where the tested compounds demonstrated a significant gastric tolerance. Interestingly, the most selective COX-1 inhibitor showed higher analgesic activity in vivo as expected compared to their moderate anti-inflammatory activity. This study underscores the need for further design and development of novel analgesic agents with low tendency to cause gastric damage based on improving their COX-1 affinity and selectivity profile.
Abdelazeem, Ahmed H.,El-Saadi, Mohammed T.,Safi El-Din, Asmaa G.,Omar, Hany A.,El-Moghazy, Samir M.
p. 665 - 676
(2016/12/30)

Synthesis of functionalized imidazolidine-2-thiones: Via NHC/base-promoted aza-benzoin/aza-acetalization domino reactions
A strategy for the synthesis of biologically relevant 5-hydroxy-imidazolidine-2-thione derivatives is presented. A novel class of α-sulfonylamines have been suitably prepared (46-81% yield) as precursors of formal benzylidenethiourea acceptors; these are generated in situ and intercepted by N-heterocyclic carbene (NHC)-activated aldehydes affording open-chain aza-benzoin-type adducts, which in turn undergo an intramolecular aza-acetalization reaction in a one-pot fashion. A thiazolium salt/triethylamine couple proved to be the more effective system to trigger the domino sequence giving the target heterocycles in good yields (45-97%) and diastereoselectivities (up to 99 : 1 dr). The multigram scale synthesis and elaboration of a selected 5-hydroxy-imidazolidine-2-thione compound is also described.
Di Carmine, Graziano,Ragno, Daniele,De Risi, Carmela,Bortolini, Olga,Giovannini, Pier Paolo,Fantin, Giancarlo,Massi, Alessandro
p. 8788 - 8801
(2017/11/03)

HPLC enantioseparation on a homochiral MOF-silica composite as a novel chiral stationary phase
The last frontier in the development of chiral stationary phases for chromatographic enantioseparation involves homochiral metal-organic frameworks (MOFs). Using enantiopure (R)-2,2′-dihydroxy-1,1′-binaphthalene-6,6′-dicarboxylic acid as a starting material, we prepared three homochiral MOFs that were further used as chiral stationary phases for high-performance liquid chromatography to separate the enantiomers of various kinds of racemic sulfoxides, sec-alcohols, β-lactams, benzoins, flavanones and epoxides. The experimental results showed excellent performances for enantioseparation, and highlighted that enantioseparation on homochiral MOF columns is practical.
Tanaka, Koichi,Muraoka, Toshihide,Otubo, Yasuhiro,Takahashi, Hiroki,Ohnishi, Atsushi
p. 21293 - 21301
(2016/03/08)

Iodine(III)-Mediated Oxidative Hydrolysis of Haloalkenes: Access to α-Halo Ketones by a Release-and-Catch Mechanism
An unprecedented iodine(III)-mediated oxidative transposition of vinyl halides has been accomplished. The products obtained, α-halo ketones, are useful and polyvalent synthetic precursors. There are only a handful of reported examples of the direct conversion of vinyl halides to their corresponding α-halo carbonyl compounds. Insights into the mechanism and demonstration that this synthetic transformation can be done under enantioselective conditions are reported.
Jobin-Des Lauriers, Antoine,Legault, Claude Y.
supporting information
p. 108 - 111
(2016/01/15)

A mild method for the replacement of a hydroxyl group by halogen. 1. Scope and chemoselectivity
α-Chloro-, bromo- and iodoenamines, which are readily prepared from the corresponding isobutyramides have been found to be excellent reagents for the transformation of a wide variety of alcohols or carboxylic acids into the corresponding halides. Yields are high and conditions are very mild thus allowing for the presence of sensitive functional groups. The reagents can be easily tuned allowing therefore the selective monohalogenation of polyhydroxylated molecules. The scope and chemoselectivity of the reactions have been studied and reaction mechanisms have been proposed.
Munyemana, Fran?ois,George, Isabelle,Devos, Alain,Colens, Alain,Badarau, Eduard,Frisque-Hesbain, Anne-Marie,Loudet, Aurore,Differding, Edmond,Damien, Jean-Marie,Rémion, Jeanine,Van Uytbergen, Jacqueline,Ghosez, Léon
p. 420 - 430
(2015/12/31)

Iron-Catalyzed α-Arylation of Deoxybenzoins with Arenes through an Oxidative Dehydrogenative Approach
A novel α-arylation of deoxybenzoins with non-prefunctionalized arenes is developed through an iron-catalyzed oxidative dehydrogenative approach. The reaction shows broad substrate scope and functional group tolerance and thus provides efficient access to synthetically useful 1,2,2-triarylethanones. A reasonable mechanism is also proposed.
Chen, Tao,Li, Yi-Fan,An, Yang,Zhang, Fu-Min
supporting information
p. 4754 - 4757
(2016/09/28)

Mechanochemical solid-state synthesis of 2-aminothiazoles, quinoxalines and benzoylbenzofurans from ketones by one-pot sequential acid- and base-mediated reactions
α-Chloroketones-obtained by the atom-economical chlorination of ketones with trichloroisocyanuric acid (TCCA) in the presence of p-TSA under ball-milling conditions-were set up for a sequential base-mediated condensation reaction with thiourea/thiosemicarbazides, o-phenylenediamine and salicylaldehyde to afford 2-aminothiazoles, 2-hydrazinylthiazoles, quinoxalines and benzoylbenzofurans, respectively, in respectable yields. The viability of one-pot sequential acid- and base-mediated reactions in the solid state under ball-milling conditions is thus demonstrated.
Nagarajaiah, Honnappa,Mishra, Abhaya Kumar,Moorthy, Jarugu Narasimha
p. 4129 - 4135
(2016/06/14)

Which one is faster? A kinetic investigation of Pd and Ni catalyzed Negishi-type oxidative coupling reactions
The difference between Pd and Ni has been investigated based on the Negishi-type oxidative coupling reactions in which reductive elimination was proved to be the rate determining step. Although DFT calculations illustrate that the Pd catalyzed reaction should be faster than the Ni catalyzed reaction under these conditions, kinetic experiments indicate that the reaction rate of Pd and Ni is dependent on the concentration of the catalyst precursor. The Pd catalyzed reaction is faster than the Ni catalyzed reaction only when the precursor concentration is as low as 1 × 10-7 M.
Xin, Jie,Zhang, Guanghui,Deng, Yi,Zhang, Heng,Lei, Aiwen
supporting information
p. 19777 - 19781
(2015/12/17)

Design and synthesis of imidazo[2,1-b]thiazole-chalcone conjugates: Microtubule-destabilizing agents
A series of chalcone conjugates featuring the imidazo[2,1- b]thiazole scaffold was designed, synthesized, and evaluated for their cytotoxic activity against five human cancer cell lines (MCF-7, A549, HeLa, DU-145 and HT-29). These new hybrid molecules have shown promising cytotoxic activity with IC50 values ranging from 0.64 to 30.9 mm. Among them, (E)-3-(6-(4- fluorophenyl)-2,3-bis(4-methoxyphenyl)imidazo[2,1-b]thiazol-5- yl)-1-(pyridin-2-yl)prop-2-en-1-one (11 x) showed potent antiproliferative activity with IC50 values ranging from 0.64 to 1.44 mm in all tested cell lines. To investigate the mechanism of action, the detailed biological aspects of this promising conjugate (11x) were carried out on the A549 lung cancer cell line. The tubulin polymerization assay and immunofluoresence analysis results suggest that this conjugate effectively inhibits microtubule assembly in A549 cells. Flow cytometric analysis revealed that this conjugate induces cell-cycle arrest in the G2/M phase and leads to apoptotic cell death. This was further confirmed by Hoechst staining, activation of caspase-3, DNA fragmentation analysis, and Annexin V-FITC assay. Moreover, molecular docking studies indicated that this conjugate (11 x) interacts and binds efficiently with the tubulin protein.
Kamal, Ahmed,Balakrishna, Moku,Nayak, V. Lakshma,Shaik, Thokhir Basha,Faazil, Shaikh,Nimbarte, Vijaykumar D.
p. 2766 - 2780
(2015/02/02)

Direct conversion of alcohols to α-chloro aldehydes and α-chloro ketones
Direct conversion of primary and secondary alcohols into the corresponding α-chloro aldehydes and α-chloro ketones using trichloroisocyanuric acid, serving both as stoichiometric oxidant and α-halogenating reagent, is reported. For primary alcohols, TEMPO has to be added as an oxidation catalyst, and for the transformation of secondary alcohols (TEMPO-free protocol), MeOH as an additive is essential to promote chlorination of the intermediary ketones.
Jing, Yuanyuan,Daniliuc, Constantin G.,Studer, Armido
supporting information
p. 4932 - 4935
(2015/04/27)

Practical approach for preparation of unsymmetric benzils from β-ketoaldehydes
An efficient and practical method for the synthesis of unsymmetric benzils from readily available β-ketoaldehydes has been developed. Various unsymmetric 1,2-diaryldiketones bearing functional groups have been obtained in good to excellent yields under mild reaction conditions. A plausible mechanism was proposed, and α,α-dichloroketone was considered as the key intermediate. The generation of α,α-dichloroketones from β-ketoaldehydes may undergo the following steps: (1) oxidation by sodium hypochlorite, (2) decarboxylation, and (3) chlorination by Cl2 generated from sodium hypochlorite.
Ruan, Libo,Shi, Min,Li, Nian,Ding, Xu,Yang, Fan,Tang, Jie
supporting information
p. 733 - 735
(2014/03/21)

Aromatic substitution in ball mills: Formation of aryl chlorides and bromides using potassium peroxomonosulfate and NaX
Aryl chlorides and bromides are formed from arenes in a ball mill using KHSO5 and NaX (X = Cl, Br) as oxidant and halogen source, respectively. Investigation of the reaction parameters identified operating frequency, milling time, and the number of milling balls as the main influencing variables, as these determine the amount of energy provided to the reaction system. Assessment of liquid-assisted grinding conditions revealed, that the addition of solvents has no advantageous effect in this special case. Preferably activated arenes are halogenated, whereby bromination afforded higher product yields than chlorination. Most often reactions are regio- and chemoselective, since p-substitution was preferred and concurring side-chain oxidation of alkylated arenes by KHSO5 was not observed. The Royal Society of Chemistry.
Schmidt, Robert,Stolle, Achim,Ondruschka, Bernd
p. 1673 - 1679
(2013/02/22)

What is the rate of the Csp2-Csp2 reductive elimination step? Revealing an unusually fast Ni-catalyzed negishi-type oxidative coupling reaction
(Graph Presented) For a direct quantitative investigation of the Csp 2-Csp2 reductive elimination rate within a catalytic cycle, a novel oxidative coupling system in the presence of a Ni catalyst and desyl chloride as the oxidant is devised. The reaction progress profiles of arylzinc reagents exhibit zero-order kinetic behavior, and a reductive elimination step is confirmed as the ratedetermining step. This allows direct measurement of the Csp2-Csp2 reductive elimination rate constant within a catalytic cycle. The rate constants of p-MePhZnCl are obtained in the range 0.23 to 3.5 s-1 from 0 to -35°C, which are unusually fast reaction rates. According to the Arrhenius equation, the values of ΔH? and ΔS? (ΔH ? = 9.7 kcal mol-1, ΔS? = 35 J mol-1 K-1) are obtained. The small value of ΔH? reveals that the reductive elimination step of Csp2-Ni-Csp2 is an extremely facile process.
Jin, Liqun,Zhang, Hua,Li, Peng,Sowa Jr., John R.,Lei, Aiwen
supporting information; experimental part
p. 9892 - 9893
(2009/12/06)

A facile synthesis of two series of multifunctional carbon compounds from α,α-dihalo ketones using allylsamarium bromide
The use of allylsamarium bromide to effect two different reactions on the common starting material, a,a-dihalo ketones, is presented. With DMF, α-halo-α-allyl aldehydes were obtained, while α-hydroxy- α-allyl aldehyde acetals were obtained in the presence of NaOMe/MeOH. Georg Thieme Verlag Stuttgart.
Liu, Xiaodan,Zhang, Songlin,Di, Jucai
experimental part
p. 2749 - 2755
(2010/01/21)

A facile one-pot synthesis of a?-halo-a?-allyl-aldehydes from a?,a?-Dihaloketoncs Using Allylsamarium Bromide and DMF
A convenient, one-pot synthesis of a range of a?-halo-a?-allyl aldehydes is described. The protocol involves the reaction of allylsamarium bromide with various a?,a?-dihalo ketones. A possible mechanism of the transformation is proposed.
Di, Jucai,Zhang, Songlin
experimental part
p. 1491 - 1494
(2009/04/07)

Synthesis and biological evaluation of analogues of the anti-tumor alkaloid naamidine A
A small series of derivatives of the alkaloid naamidine A was synthesized and tested in vitro for their ability to inhibit mitogenesis in BaF/ERX cells. Replacement of the imidazole core with a thiazole was found to have only a minor effect on potency, and the 4-methoxybenzyl substituent of the natural product was shown to be unnecessary for activity.
Aberle, Nicholas,Catimel, Jenny,Nice, Edouard C.,Watson, Keith G.
p. 3741 - 3744
(2008/02/12)

Conversion of hydrazones to alkyl chlorides under Swern oxidation conditions
The unsubstituted hydrazones derived from aromatic ketones and aldehydes were converted in high yield to the corresponding alkyl chlorides under Swern oxidation conditions. In this unusual oxidation/reduction sequence the substrate undergoes a net reduction under the well established Swern oxidation conditions. Unsubstituted hydrazones derived from cyclohexyl ketones returned elimination products.
Brewer, Matthias
p. 7731 - 7733
(2007/10/03)

Electrophilic amination of enolates with oxaziridines: Effects of oxaziridine structure and reaction conditions
A range of N-alkoxycarbonyl- and N-carboxamido-oxaziridines has been prepared to test the effects of oxaziridine structure on yields of enolate amination product. Side-products arising from reaction of aldehyde-derived oxaziridines with base were identified, while a ketone-derived oxaziridine afforded moderate yields of amination product with stabilised carbanions.
Armstrong, Alan,Edmonds, Ian D.,Swarbrick, Martin E.,Treweeke, Nigel R.
p. 8423 - 8442
(2007/10/03)

Chemical oxidation studies of β-hydroxysulfides with tris(4-bromophenyl)aminium hexachloroantimonate: Diastereoselective sulfoxide obtaining and pinacol-type rearrangement
The chemical oxidation of some β-hydroxy-sulfides in the presence of tris(4-bromo-phenyl)aminium hexachloroantimonate (TBPA) is reported. The oxidation of 2-ethylsulfanyl-cyclohexan-1-ol (cis- and trans-) resulted the corresponding sulfoxides with good diastereoselectivity (d.e. 50%) and for 2-methyl-2-ethylsulfanyl-cyclohexan-1-ol and 2-ethylsulfanyl-1,2-diphenyl-ethanol, the corresponding nonsulfanylated ketones (61-75%) and ethyl ethanethiolsulfonate (51-65%) were obtained via oxidative cleavage and pinacol-type rearrangement.
Donnici, Claudio Luis,Guimaraes, Sibele,De Melo, Angelita Cristine
p. 1489 - 1497
(2007/10/03)

Transition metal-catalyzed oxidations. 12 : α-Chlorination of silylenol ethers with tert-butyl hydroperoxide and TiCl2(OiPr)2
Enolsilyl ethers (4, 6, 8, 10, 12, 14) are chlorinated to the α-monochloro ketones (5, 7, 9, 11, 13, 15) with tert-butyl hydroperoxide in the presence of dichlorotitanium diisopropoxide in 69 - 92% yield. WILEY-VCH Verlag GmbH, 1999.
Krohn, Karsten,Steingroever, Klaus,Vinke, Ingeborg
p. 62 - 64
(2007/10/03)

Substituent Effects on the Strength of C-C Bonds, 14. - Kinetic and Thermodynamic Stability of 2,3-Bis(dialkylamino)-1,4-diketones - Energy of Stabilization of α-Dialkylamino α-Carbonylalkyl Radicals with Capto-dative Substituents
The equilibrium constants and rate constants for the dissociation of the 2,3-bis(dialkylamino)-1,4-diketone diastereomers meso- and DL-7a and 7b were measured over a temperature range of 40 deg C.From the enthalpies of dissociation ΔHDiss and ethalpies of activation ΔH(excit.) and the strain enthalpies of 7 the bond dissociation enthalpies BDE(C-C) of 7 were determined.By comparison with the dissociation enthalpies of Ct-Ct alkanes the change of these BDEs(C-C) by the capto-dative substitution was determined to be 85.4 kJ mol-1 (20.4 kcal mol-1).The heats of formation ΔHf0(g) of a series of amino ketones 8 were determined from their heats of combustion and their heats of evaporation.From the ΔHf0(g) values in combination with MM2 calculations of their strain enthalpies strain-free increments CHn2-n> with n = 0, 1, 2 were derived and geminal interaction enthalpies in the ground states were obtained thereof.The radical stabilization enthalpy RSE of 6 was deduced from the ΔBDE(C-C) values and the ground state effect to be 73.6 kJ mol-1 (17.6 kcal mol-1).From these data and the radical stabilization enthalpies RSE of α-aminoalkyl radicals (4.2 kJ mol-1) and α-carbonyl radicals (28.9 kJ mol-1) a synergetic radical stabilization enthalpy of 40.5 kJ mol-1 (9.7 kcal mol-1) is deduced.This number combines "extra" resonance stabilization and general inductive or anomeric geminal substituent interaction in the radicals.The crystal structure of meso-7a has been determined by X-ray diffraction methods. - Key Words: C-C Bond cleavage, kinetics of / Heats of formation / Radicals, stability of / Capto-dative effect / Geminal substituents, energetic interaction of
Welle, Frank,Verevkin, Sergej P.,Keller, Manfred,Beckhaus, Hans-Dieter,Ruechardt, Christoph
p. 697 - 710
(2007/10/02)

Unusual redox behavior in the photoinduced electron-transfer reactions of amino ketones
Irradiation of a wet benzene solution of 1,2-diphenyl-2-piperidino-l-ethanone and 9,10-dicyanoanthracene leads to the formation of benzil and deoxybenzoin. We have interpreted these products as arising from deprotonation leading to net oxidation coupled with reductive elimination. The latter pathway is noteworthy in that we show reductive elimination of an electron donor can be a chief consequence of photochemical single electron transfer (SET) quenching.
Bergmark, William R.,Dewan, Charlotte,Whitten, David G.
p. 8810 - 8812
(2007/10/02)

REACTION OF PHENYLCHLOROCARBENE WITH ACETALS
The reaction of phenylchlorocarbene generated from benzylidene chloride and potassium tert-butoxide with 2-aryl-1,3-dioxolanes gave the products from insertion of the carbene into the C2-H bond of the substituted dioxolane.The main product in the reaction of the same carbene with benzaldehyde dimethyl acetal is benzyl benzoate.
Dement'eva, L. P.,Kostikov, R. R.
p. 117 - 118
(2007/10/02)

OXIDATION OF OLEFINS USING CHROMIC ANHYDRIDE-CHLOROTRIMETHYLSILANE. A CONVENIENT SYNTHESIS OF α-CHLORO KETONES.
Disubstituted internal olefins are oxidized selectively to α-chloro ketones in excellent yields from the reaction with chromic anhydride-chlorotrimethylsilane in carbon tetrachloride.
Lee, Jong Gun,Ha, Dong Soo
p. 193 - 196
(2007/10/02)

THE REACTION OF α,α-DICHLOROBENZYLTRIMETHYLSILANE WITH ALDEHYDES AND KETONES.
The reaction of α,α-dichlorobenzyltrimethylsilane with carbonyl compounds in the presence of fluoride ion fails to give reasonable yields of the α,α-dichlorobenzyl adducts except when carried out in the presence of zinc iodide and in HMPA as solvent.Under these conditions moderate yields of the adducts can be obtained with cyclohexanone, cyclohexenone, benzaldehyde and trans cinnamaldehyde.These reactions were compared with those of α,α-dichlorobenzyllithium.
Larson, Gerald L.,Prieto, Jose A.,Valle, Luis del
p. 1405 - 1412
(2007/10/02)

Synthesis of Oxazoles by the Reaction of Ketones with Iron(III) Solvates of Nitriles
Oxazoles having functionalized carbon substituents at the C-2 position were synthesized in one step by the oxidation of ketones with iron(III) solvates of nitriles, i.e., Fe(RCN)6(ClO4)3(solvate A) or Fe(RCN)6)FeCl4)3(solvate B), in the corresponding nitriles.Keywords oxazole; ketone; oxidation; nitrile; iron(III) nitrile solvate
Kotani, Eiichi,Kobayashi, Shigeki,Adachi, Mayumi,Tsujioka, Toshiyuki,Nakamura, Kouji,Tobinaga, Seisho
p. 606 - 609
(2007/10/02)

Reaction of four-membered cyclic nitrones with acetyl chloride. X-Ray crystal structures of 2--N,N-diethyl-2-methyl-4-oxo-3-phenylpentanamide and 1-acetyl-3-chloro-N,N-diethyl-2-methyl-4-methylene-3-phenyl-2-azetidinecarboxamide
Reactions of the four-membered cyclic nitrones 1 with acetyl chloride differ strongly from those of other (cyclic) nitrones.In the presence of water, the nitrones 1 yield the 2--N,N-diethylalkanamides 4.The structure of 4b was confirmed by X-ray analysis.In the absence of water, the N,N-diethyl-4-methylene-2-azetidinecarboxamides 5 or the N,N-diethyl-2,3-dihydro-2-azetecarboxamides 6 were obtained.X-ray analysis elucidated the structure of 5a.Under acidic conditions, compound 5a yielded the 2-oxa-5-azabicyclohexan-3-one derivative 13.Acid hydrolysis of 6a gave the α-chloroketone derivative 18 and the 2-oxopropanamide derivative 19.
Eijk, Peter J. S. S. van,Trompenaars, Willem P.,Reinhoudt, David N.,Harkema, Sybolt
p. 52 - 62
(2007/10/02)

Reaction of α,β-Unsaturated Carboxylic Acids with Manganese(III) Acetate in the Presence of Chloride Ion
The reaction of 3-phenylpropenoic acids with manganese(III) acetate - Cl- complex yielded 1,2,2-trichloro-1-phenylethanes, 1-acetoxy-2,2-dichloro-1-phenylethanes, and 2,2-dichloro-1-phenylethanols. (E)-2,3-Diphenylpropenoic acids gave 2,2-dichloro-1,2-diphenylethanones and 2-acetoxy-1,2-diphenylethanones. 3,3-Diphenylpropenoic acids yielded 2,2-dichloro-1,1-diphenylethenes, 1-acetoxy-2,2-dichloro-1,1-diphenylethanes, 2,2-dichloro-1,1-diphenyl-1-ethanols, and 2-hydroxy-2,2-diphenylethanal.Fluorenylideneacetic acid gave 9-chloro-9-(dichloromethyl)fluorene, 9-acetoxy-9-(dichloromethyl)fluorene, and 9-fluorenone. 1-Cyclohexenecarboxylic acid yielded 1,2-dichlorocyclohexanecarboxylic acid and 1-acetoxy-2-chlorocyclohexanecarboxylic acid.The reaction can be explained in terms of a free-radical mechanism involving manganese(III) acetate - Cl- complexation, addition of Cl. radical, decarboxylation, and the oxidation of chloroethenes which are the reaction intermediates.
Yonemura, Hiroshi,Nishino, Hiroshi,Kurosawa, Kazu
p. 3153 - 3160
(2007/10/02)

A COMPARISON OF THE DECOMPOSITION OF A 3-NITRENO-1,3-OXAZOLIN-2-ONE AND THE ISOMERIC 1,3,4-OXADIAZIN-2-ONE
The oxidation of 3-amino-4,5-diphenyl-1,3-oxazolin-2-oe (7) affords monodiazobenzyl 10 as the primary decomposition product of N-nitrenolactam 1.In contrast, the oxidation 3,6-dihydro-5,6-diphenyl-1,3,4-oxadiazin-2-one (6) leads to diphenylacetylene (12) via oxadiazin-2-one 2.
Wilson, R. Marshall,Chow, Tahsin J.
p. 4635 - 4636
(2007/10/02)

Unusual and Competitive Side Reactions during C-Alkylation of Indan-1,3-dione
Direct C-alkylation of indan-1,3-dione (I) with reactive alkyl halides under mild conditions leads to the formation of 2-alkyl-indan-1,3-dione (II) along with bis-alkylated derivative (III) and traces of 2-alkylated bindone (a self-condensation of indan-1,3-dione).The isolation and characterisation of these compounds are described.
Padmanabhan, P. V.,Ramana, D. V,Ramadas, S. R.
p. 1 - 4
(2007/10/02)

Some new Schiff base derivatives derived from vanillin as possible fungicides
-
Dash,Patra,Mahapatra
p. 772 - 774
(2007/10/02)

Metal-Catalyzed Organic Photoreactions. One-Step Synthesis of Chlorinated Ketones from Olefins by Photooxidation in the Presence of Iron(III) Chloride
Under photooxidation in pyridine in the presence of FeCl3, mono- and disubstituted olefins gave α-chloro ketones, while tri- and tetrasubstituted olefins gave dichloro ketones with a C-C bond cleavage.The reaction was interpreted in terms of an electron-transfer mechanism occurring within the coordination sphere of the iron ion
Kohda, Akira,Ueda, Keiko,,Sato, Tadashi
p. 509 - 515
(2007/10/02)

Mechanism of Base-catalysed Hydrogen-Deuterium Exchange in Thiazolium Ion: Evidence for the Involvement of a Tetrahedral Intermediate
The mechanism of base-catalysed hydrogen-deuterium exchange of 2-H in the thiazolium ion has been examined by 1H n.m.r. spectroscopy, using small and sterically hindered nucleophiles.Rapid H-D exchange is observed in Me2SO in the cases of 3,4,5-trimethyl- (1), 3-methyl-4,5-diphenyl- (2), 3,5-dimethyl-4-phenyl- (3), and 3,4-dimethyl-5-phenyl-thiazolium iodide (4), when small nucleophiles (KOD-D2O or KOCD3-DOCD3; 0.016M; 25 deg C) are employed.Utilization of a hindered nucleophile however results in a slow exhange of 2-H in (1), (3), and (4), concomitant with H-D exchange of the 4- and 5-methyl exchange of 2-H is detected in the case of (2) with the hindered nucleophile.These observations are ascribed to the formation of a tetrahedral intermediate as a prerequisite of the exchange reaction.
Karimian, Khashayar,Mohtarami, Fatemeh,Askari, Massoud
p. 1538 - 1543
(2007/10/02)

Azole derivatives
Azole derivatives of the formula SPC1 Wherein R1 is free or esterified carboxyl or other functionally modified carboxyl group, R2 and R3 each are aryl; A is Cn H2n in which n is an integer from 1 to 10, inclusive; and Z is O or S; and the physiologically acceptable salts thereof, possess, with good compatibility, excellent antiphlogistic activity and, in particular, influence favorably the chronic progressive diseases of the joints, e.g., arthritis. They can be prepared from compounds of the formula SPC2 Wherein X1 is a group convertible into the group --S--A--R1, and R2 and R3 have the values given above.
-
(2008/06/13)