- OPTICAL INDUCTION - IV Optical Induction by Using Homogeneous Catalyst
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Better optical induction during Michael addition has been achieved by using new homogeneous catalysts based on quinine and quinidine.
- Ahuja, R. R.,Natu, A. A.,Gogte, V. N.
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- Catalyst-free chemoselective α-sulfenylation/β-thiolation for α,β-unsaturated carbonyl compounds
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A novel, efficient, catalyst-free and product-controllable strategy has been developed for the chemoselective α-sulfenylation/β-thiolation of α,β-unsaturated carbonyl compounds. An aromatic sulfur group could be chemoselectively introduced at α-or β-posit
- Huang, Xi,Li, Juan,Li, Xiang,Wang, Jiayi,Peng, Yanqing,Song, Gonghua
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p. 26419 - 26424
(2019/09/13)
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- SmI2-mediated reductive cyclization of β-arylthio ketones: A facile and diastereoselective synthesis of thiochroman derivatives
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SmI2-mediated reductive cyclization of β-arylthio ketones to generate thiochroman derivatives is not a generally observed process and the reported examples are limited to geminal disubstitution in the substrates. The results of the current stud
- Mao, Hui,You, Bing-Xin,Zhou, Lie-Jin,Xie, Ting-Ting,Wen, Yi-Hang,Lv, Xin,Wang, Xiao-Xia
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p. 6157 - 6166
(2017/08/02)
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- NMR and DFT Insight into the Synergistic Role of Bovine Serum Albumin–Ionic Liquid for Multicomponent Cascade Aldol/Knoevenagel–thia-Michael/Michael Reactions in One Pot
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The synergistic combination of two catalysts is an emerging strategy towards the formation of unprecedented complex molecules, and herein bovine serum albumin (BSA) and the neutral ionic liquid 1-butyl-3-methylimidazolium bromide ([bmim]Br) are used together for the first time towards multiple C?C and C?S bond-formation reactions in one pot under metal-free, acid-free, and base-free conditions by merging two classical named reactions, that is, aldol condensation (AC) and thia-Michael addition (TMA) for the cascade chemoselective generation of β-aryl-β-sulfido carbonyl compounds from aliphatic ketones, aromatic aldehydes, and thiols. NMR spectroscopy and DFT calculations studies provided insight into the synergism, progress, and mechanism of the reaction, and control experiments highlighted that the single catalysts (BSA or IL) alone did not allow even the first AC step to proceed. Moreover this synergistic BSA–[bmim]Br catalytic system offers the step-economical synthesis of the anticoagulant warfarin through sequential aldol–Michael addition reactions and potent pyridine analogues through a Knoevenagel–Michael route. Besides, the recyclability of the catalytic system (up to 5 times) with the generation of water as a byproduct makes our one-pot protocol more economically efficient and synthetically attractive than traditional methods.
- Thopate, Yogesh,Singh, Richa,Sinha, Arun K.,Kumar, Vikash,Siddiqi, Mohammad Imran
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p. 3050 - 3056
(2016/10/11)
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- Thioboration of α,β-unsaturated ketones and aldehydes toward the synthesis of β-sulfido carbonyl compounds
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Herein a direct β-sulfido carbonyl compound synthesis by the easy activation of RS-Bpin reagents with α,β-unsaturated ketones and aldehydes is reported. This convenient methodology can be performed at room temperature with no other additives. The key poin
- Civit, Marc G.,Sanz, Xavier,Vogels, Christopher M.,Webb, Jonathan D.,Geier, Stephen J.,Decken, Andreas,Bo, Carles,Westcott, Stephen A.,Fernández, Elena
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supporting information
p. 2148 - 2154
(2015/05/19)
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- Sonochemical synthesis of lithium fluoride nano cubic as an active and simple catalyst for thia-Michael addition process: Synthesis and structural characterization of β-aryl-β-mercapto ketones
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LiF nano cubic, with an average particle size of 21.6 nm, was synthesized sonochemically, using tetrabutylammonium fluoride as the fluoride source and characterized by SEM-EDX and XRD. This was applied, as a heterogeneous nano-catalyst, to synthesize some
- Shobeiri, Zohreh,Pourayoubi, Mehrdad,Neas, Marek,Divjakovic, Vladimir,Babiak, Michal
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p. 245 - 255
(2015/02/19)
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- Synthesis of β-sulfanyl ketones via a tandem rearrangement-conjugate addition reaction catalyzed by a Re(V)-oxo complex
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A method for synthesizing β-sulfanyl ketones via a tandem rearrangement and conjugate addition reaction has been developed. This methodology provides access to a range of β-sulfanyl ketones through the rearrangement of propargyl alcohols to the corresponding enones followed by the conjugate addition of unactivated thiols. The one-pot, tandem transformation is catalyzed by ReOCl3(OPPh3)(S(CH3)2) affording aryl and alkyl β-sulfanyl ketones in good to excellent yield.
- Garst, Alyson E.,Badiceanu, Alexandra D.,Nolin, Kristine A.
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supporting information
p. 459 - 461
(2013/02/23)
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- E-factor minimized protocols for the polystyryl-BEMP catalyzed conjugate additions of various nucleophiles to α,β-unsaturated carbonyl compounds
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Efficient protocols for the addition of carbon-, sulphur- and nitrogen-nucleophiles to α,β-unsaturated carbonyl compounds catalyzed by PS-BEMP have been reported. The adoption of solvent-free conditions (SolFC) was crucial for improving the efficiency of all the processes, while by using an organic reaction medium poor results were obtained. Addition reactions were performed by using equimolar amounts of reagents, and the products were isolated by simple filtration with the minimal amount of organic solvent. This approach allowed the E-factor, a measure of the waste of a reaction, to be minimized. Further waste minimization (95.7% compared to batch protocol) has been accomplished by defining a larger scale continuous-flow protocol operating under SolFC.
- Bonollo, Simona,Lanari, Daniela,Longo, Julie M.,Vaccaro, Luigi
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supporting information; experimental part
p. 164 - 169
(2012/04/04)
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- Conjugate addition of unactivated thiols to α,β-unsaturated ketones catalyzed by a bifunctional rhenium(V)-oxo complex
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ReOCl3(OPPh3)(S(CH3)2) has been found to be an efficient bifunctional catalyst for the 1,4-addition of thiols to α,β-unsaturated ketones. The addition of thiophenol derivatives and alkyl thiols proceeds under mi
- Peng, Allan,Rosenblatt, Ross,Nolin, Kristine
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supporting information; experimental part
p. 2712 - 2714
(2012/07/14)
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- JandaJel as a polymeric support to improve the catalytic efficiency of immobilized-1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) under solvent-free conditions
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JandaJel, with its greater spacing between the linear polymeric chains compared to that of polystyrene matrices, is a very efficient support for improving the catalytic efficiency of TBD under SolFC. The Royal Society of Chemistry.
- Lanari, Daniela,Ballini, Roberto,Bonollo, Simona,Palmieri, Alessandro,Pizzo, Ferdinando,Vaccaro, Luigi
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supporting information; experimental part
p. 3181 - 3186
(2011/12/04)
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- Sc(III)-catalyzed enantioselective addition of thiols to α,β-unsaturated ketones in neutral water
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Chemical equations presented. This report concerns Lewis acid catalyzed enantioselective sulfa-Michael addition in neutral water by using a very efficient Sc(OTf)3/bipyridine 1 catalytic system. It is noteworthy that the protocol presented empl
- Bonollo, Simona,Lanari, Daniela,Pizzo, Ferdinando,Vaccaro, Luigi
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supporting information; body text
p. 2150 - 2152
(2011/06/21)
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- Ionic liquid catalysed reaction of thiols with α,β-unsaturated carbonyl compounds-remarkable influence of the C-2 hydrogen and the anion
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Hydrogen bond induced reactivity and selectivity control in the 1-butyl-3-methylimidazolium based ionic liquid catalysed reaction of thiols with α,β-unsaturated carbonyl compounds is reported with remarkable influence of the anion and the C-2 hydrogen in
- Sarkar, Anirban,Roy, Sudipta Raha,Chakraborti, Asit K.
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supporting information; experimental part
p. 4538 - 4540
(2011/06/22)
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- Squaric acid as an impressive organocatalyst for Michael addition in water
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A simple, green, and environmentally benign protocol for squaric acid (5 mg) catalyst conjugate addition of aromatic amines and thiols to unsaturated carbonyl compounds in water in good to excellent yields is developed. The advantages of low sensitivity toward moisture and oxygen, high tolerance of different functional groups, green reaction media and efficient recyclability make this organocatalyst suitable for both laboratory and industrial scale synthesis of β-substituted carbonyls under very mild conditions.
- Azizi, Najmadin,Saki, Elham,Edrisi, Mahtab
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experimental part
p. 973 - 977
(2012/05/20)
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- Chiral lanthanoid dimers ligated by carbohydrate-based diketonates: Catalytic and luminescent properties
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The reaction of hydrated lanthanoid chlorides (Ln = La, Eu) with chiral, carbohydrate-based diketonate ligands has yielded dimeric species with Ln 2L6 composition as determined by MALDI mass spectrometry and single-crystal X-ray crystallography. The X-ray crystallographic analysis identified a chiral cavity formed by interligand repulsion able to coordinate dimethylformamide, prompting investigation of the catalytic properties of the dimers. Preliminary results indicate that the dimers display catalytic activity in thio-Michael addition reactions as well as metal-based luminescence in the case of europium.
- Gee, William J.,Hierold, Judith,MacLellan, Jonathan G.,Andrews, Philip C.,Lupton, David W.,Junk, Peter C.
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experimental part
p. 3755 - 3760
(2011/11/14)
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- Rongalite and base-promoted cleavage of disulfides and subsequent Michael addition to α,β-unsaturated ketones/esters: an odorless synthesis of β-sulfido carbonyl compounds
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A highly practical method to access β-sulfido carbonyl compounds was developed, which could be conducted without any expensive reagent, special apparatus/technique, and no requirement of metal catalysts. β-Sulfido carbonyl compounds were formed at room temperature, in short time and with high chemoselectivity in good to excellent yields. A plausible mechanism for the role of Rongalite, as a promoter for the cleavage of disulfides generating thiolate anions that then undergo facile thia-Michael addition to α,β-unsaturated ketones and esters is proposed.
- Guo, Wenxue,Lv, Guangshu,Chen, Jiuxi,Gao, Wenxia,Ding, Jinchang,Wu, Huayue
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supporting information; experimental part
p. 2297 - 2300
(2010/06/16)
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- Efficient synthesis of vinyl and alkyl sulfides via hydrothiolation of alkynes and electron-deficient olefins using soluble and heterogenized gold complexes catalysts
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Soluble and heterogenized gold complexes catalyze the hydrothiolation of alkynes and electron-deficient olefins in high yields and with high anti-Markovnikov selectivity. Moreover heterogenized catalysts could be recycled in several successive runs withou
- Corma, Avelino,González-Arellano, Camino,Iglesias, Marta,Sánchez, Félix
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scheme or table
p. 49 - 54
(2010/08/06)
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- Fluoroboric acid adsorbed on silica-gel (HBF4-SiO2) as a new, highly efficient and reusable heterogeneous catalyst for thia-Michael addition to α,β-unsaturated carbonyl compounds
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Fluoroboric acid adsorbed on silica-gel (HBF4-SiO2) has been found to be a new and highly efficient heterogeneous catalyst for thia-Michael addition to α,β-unsaturated carbonyl compounds under solvent-free conditions. In the case of
- Sharma, Gaurav,Kumar, Raj,Chakraborti, Asit K.
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p. 4272 - 4275
(2008/09/21)
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- Organocatalytic asymmetric sulfa-michael addition to α,β- unsaturated ketones
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The highly enantioselective organocatalytic sulfa-Michael addition to α,β-unsaturated ketones has been accomplished using benzyl and tert-butyl mercaptans as the sulfur-centered nucleophiles. Optically active products are obtained in high yields and good
- Ricci, Paolo,Carlone, Armando,Bartoli, Giuseppe,Bosco, Marcella,Sambri, Letizia,Melchiorre, Paolo
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body text
p. 49 - 53
(2009/04/08)
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- Scope and limitations of HClO4-SiO2 as an extremely efficient, inexpensive, and reusable catalyst for chemoselective carbon-sulfur bond formation
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The scope and limitations of perchloric acid adsorbed on silica gel (HClO4-SiO2) as a highly efficient, inexpensive, and reusable catalyst for chemoselective carbon-sulfur bond formation by conjugate addition of thiols to α,β-unsatur
- Khatik, Gopal L.,Sharma, Gaurav,Kumar, Raj,Chakraborti, Asit K.
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p. 1200 - 1210
(2007/10/03)
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- Ceric ammonium nitrate (CAN) as a green and highly efficient promoter for the 1,4-addition of thiols and benzeneselenol to α,β-unsaturated ketones
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A mild and efficient process for the 1,4-addition of thiols and benzeneselenols to various α,β-unsaturated ketones using a catalytic amount of CAN with excellent product yields is described. This inexpensive, nontoxic, and readily available catalytic ceric(IV) ammonium nitrate system efficiently catalyzes conjugate addition reactions between thiol derivatives and various α,β-unsaturated ketones under solvent-free conditions. A plausible mechanism for the role of CAN, both as a promoter in free radical chain addition reactions as well as a catalyst for the conjugate addition process is proposed.
- Chu, Cheng-Ming,Gao, Shijay,Sastry,Kuo, Chun-Wei,Lu, Chaowei,Liu, Ju-Tsung,Yao, Ching-Fa
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p. 1863 - 1871
(2007/10/03)
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- Borax as an efficient metal-free catalyst for hetero-Michael reactions in an aqueous medium
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Borax, a naturally occurring material, very efficiently catalyzed the conjugate addition of thiols, dithiols and amines to α,β-unsaturated ketones, nitriles, amides, aldehydes and esters in an aqueous medium to afford the corresponding Michael adducts in good yields at room temperature. Recycling of the catalyst and scaling up of the reactions are important attributes of this catalysis. The reactions of thiols and dithiols were relatively more facile than those of the corresponding amines. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
- Hussain, Sahid,Bharadwaj, Saitanya K.,Chaudhuri, Mihir K.,Kalita, Harjyoti
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p. 374 - 378
(2007/10/03)
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- The iron(III) chloride-mediated 1,4-addition of mercaptans to α,β-unsaturated ketones and esters under solvent free conditions
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The 1,4-addition of various thiols to α,β-unsaturated ketones was completed rapidly in the presence of a catalytic amount (2-3 mol %) of anhydrous iron(III) chloride under solvent free conditions and an air atmosphere. Anhydrous iron(III) chloride is more active than that of other ferric salts. With more reactive and/or less steric reagents (1a-c and/or 2a-2c), expeditious conditions (short reaction times at room temperature) could be employed. With less reactive and/or steric reagents (1d-g and/or 2d-e), a slight increase in reaction time was required, but high yields were obtained. The FeCl3 catalyst causes preferential interactions with α,β-unsaturated ketones present in the reaction.
- Chu, Cheng-Ming,Huang, Wan-Ju,Lu, Chaowei,Wu, Pohsi,Liu, Ju-Tsung,Yao, Ching-Fa
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p. 7375 - 7380
(2007/10/03)
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- L-proline catalyzed michael additions of thiophenols to α,βunsaturated compounds, particularly α-enones, in the ionic liquid [bmim]PF6
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L-Proline catalyzed additions of 13 different thiols to 11 different a-enone Michael acceptors in [bmim] PF6 are reported. Reasonable to high yields of the reaction products were isolated in most cases.
- Kotrusz, Peter,Toma, Stefan
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p. 197 - 205
(2007/10/03)
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- Michael addition of thiols to α-enones in ionic liquids with and without organocatalysts
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Seventeen organocatalyts were tested for their ability to catalyst the addition of thiophenols to chalcones in [bmim]PF6. The products were isolated in high yield after a short reaction time, but no stereoselectivity was observed. The reactions
- Meciarova, Maria,Toma, Sefan,Kotrusz, Peter
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p. 1420 - 1424
(2007/10/03)
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- H3PW12O40 as a useful recyclable heterogeneous catalyst for the facile and highly efficient Michael addition reaction of thiols to α,β-unsaturated ketones
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Solid H3PW12O40 is easily used as a heterogeneous, reusable and efficient catalyst (1 mol%) for the selective addition of thiols and dithiols to α,β-unsaturated ketones in MeCN to afford the corresponding Michael adducts i
- Firouzabadi, Habib,Iranpoor, Nasser,Jafari, Abbas Ali
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p. 299 - 303
(2007/10/03)
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- Iodine-catalyzed Michael addition of mercaptans to α,β- unsaturated ketones under solvent-free conditions
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A simple and efficient method for the Michael reaction between various mercaptans and α,β-unsaturated ketones using a catalytic amount of iodine (5 mol %) to generate the 1,4-adduct has been reported. The significant features of the iodine catalyzed Micha
- Chu, Cheng-Ming,Gao, Shijay,Sastry,Yao, Ching-Fa
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p. 4971 - 4974
(2007/10/03)
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- Zinc perchlorate hexahydrate catalysed conjugate addition of thiols to α,β-unsaturated ketones
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Zn(II) perchlorate hexahydrate has been found to be a new and efficient catalyst for conjugate addition of thiols to α,β-unsaturated ketones under solvent-free conditions at room temperature. The reaction of aryl, arylalkyl and alkyl thiols with cyclic an
- Garg, Sanjeev K.,Kumar, Raj,Chakraborti, Asit K.
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p. 1370 - 1374
(2007/10/03)
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- Copper(II) tetrafluoroborate as a novel and highly efficient catalyst for Michael addition of mercaptans to α,β-unsaturated carbonyl compounds
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Copper(II) tetrafluoroborate has been found to be a new and highly efficient catalyst for Michael addition of thiols to α,β-unsaturated carbonyl compounds under solvent-free conditions and in H2O at room temperature. The reactions are very fast
- Garg, Sanjeev K.,Kumar, Raj,Chakraborti, Asit K.
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p. 1721 - 1724
(2007/10/03)
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- Micellar solution of sodium dodecyl sulfate (SDS) catalyzes facile Michael addition of amines and thiols to α,β-unsaturated ketones in water under neutral conditions
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Sodium dodecyl sulfate (SDS) catalyzes facile Michael additions of amines and thiols to α,β-unsaturated ketones under neutral micellar conditions to afford the corresponding Michael adducts in good to high yields.
- Firouzabadi,Iranpoor,Jafari
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p. 655 - 661
(2007/10/03)
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- THE AdNSNE MECHANISM IN THE REACTION OF PHENOL AND BENZENETHIOL WITH α-BROMO MICHAEL ACCEPTORS IN THE K2CO3-ACETONE SYSTEM
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In the reaction of α-bromo Michael acceptors with either phenol or benzenethiol formal substitution of the vinylic bromine proceeds through addition of the phenolic reagent, followed by nucleophilic substitution and β-elimination (AdNSNE mechanism) in the system K2CO3-acetone.The process is shown to be stereospecific in the case of 2a,b and 3b,c, leading to the corresponding Z isomer.The reactivity of substrates 1-4 is discussed in terms of their structural features.
- Rosnati, Vittorio,Saba, Antonio,Salimbeni, Aldo,Vettori, Umberto
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p. 249 - 256
(2007/10/02)
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- Synthesis of Heterocyclic Compounds : Part XXIV - Synthesis of 2,4-Disubstituted Thianaphthalenium Perchlorates and Thiachromans
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Cyclodehydration of β-phenylmercaptopropyl phenyl ketone (V) and β-phenyl-β-phenylmercaptoethyl methyl ketone (VI) with 70percent perchloric acid gives a mixture of 2-methyl-4-phenylthianaphthalenium perchlorate (X), 4-methyl-2-phenylthianaphthalenium per
- Devdhar, R. S.,Gogte, V. N.,Tilak, B. D.
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p. 1014 - 1018
(2007/10/02)
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