- How Water in Aliphatic Solvents Directs the Interference of Chemical Reactivity in a Supramolecular System
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Water is typically considered to be insoluble in alkanes. Recently, however, monomerically dissolved water in alkanes has been shown to dramatically impact the structure of hydrogen-bonded supramolecular polymers. Here, we report that water in methylcyclo
- Mabesoone, Mathijs F. J.,Ter Huurne, Gijs M.,Palmans, Anja R. A.,Meijer
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- SYNTHESIS OF NEW CHIRAL PHASE-TRANSFER CATALYSTS AND THEIR APPLICATION TO MICHAEL ADDITIONS.
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A series of chiral onium salts derived from (L)-( plus )-methionine have been examined for the catalysis of Michael additions in phase-transfer conditions. The chemical yields are high, but no asymmetric induction was observed. One particular catalyst rep
- Banfi,Cinquini,Colonna
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Read Online
- The study of biocatalyzed thio-Michael reaction: A greener and multi-gram protocol
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This Letter introduces a new, cheap and green protocol for the thio-Michael reaction. Here we applied three free enzymes such as lipase from pancreas porcine, chymosin and papain and an immobilized one: the Liposyme. The reactions were executed at room te
- Rizzo, Paula V.S.,Boarin, Ligia A.,Freitas, Ingridhy O.M.,Gomes, Roberto S.,Beatriz, Adilson,Rinaldi, Andrelson W.,Domingues, Nelson Luís C.
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Read Online
- Zinc complexes supported by pyridine-: N -oxide ligands: Synthesis, structures and catalytic Michael addition reactions
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New dipyridylpyrrole N-oxide ligands HL1 and HL2 are designed and synthesized via oxidation of 2-(5-(pyridin-2-yl)-1H-pyrrol-2-yl)pyridine (Hdpp) by using 3-chloroperbenzoic acid (m-CPBA) in CH2Cl2. The treatment of ZnEt2 with two equiv. of HL1 and HL2 af
- Chen, Ze-Wen,He, Piao,Liu, Chao,Mo, Xiu-Fang,Tong, Hai-Xia,Xiong, Chang-Feng,Yi, Xiao-Yi
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p. 12365 - 12371
(2020/10/02)
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- Method for synthesizing beta-thiocarbonyl compound by taking aryl sulfonyl chloride as sulfur source
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The invention discloses a method for synthesizing a beta-thiocarbonyl compound by taking aryl sulfonyl chloride as a sulfur source, comprising the following steps of: in an air atmosphere, adding arylsulfonyl chloride, ketene, triphenylphosphine, potassiu
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Paragraph 0042; 0043; 0044; 0045
(2020/11/09)
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- Cooperative catalysis with block copolymer micelles: A combinatorial approach
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A rapid approach to identifying complementary catalytic groups using combinations of functional polymers is presented. Amphiphilic polymers with "clickable" hydrophobic blocks were used to create a library of functional polymers, each bearing a single functionality. The polymers were combined in water, yielding mixed micelles. As the functional groups were colocalized in the hydrophobic microphase, they could act cooperatively, giving rise to new modes of catalysis. The multipolymer "clumps" were screened for catalytic activity, both in the presence and absence of metal ions. A number of catalyst candidates were identified across a wide range of model reaction types. One of the catalytic systems discovered was used to perform a number of preparative-scale syntheses. Our approach provides easy access to a range of enzyme-inspired cooperative catalysts.
- Bukhryakov, Konstantin V.,Desyatkin, Victor G.,O'Shea, John-Paul,Almahdali, Sarah R.,Solovyeva, Vera,Rodionov, Valentin O.
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supporting information
p. 76 - 80
(2015/03/05)
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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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p. 2148 - 2154
(2015/05/19)
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- Direct Michael addition to electron-deficient alkenes using diorganyl dichalcogenides (Te/S) and NaBH4/PEG-400
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Nucleophilic species of tellurium and sulfur were generated in situ from the reaction of the respective diorganyl dichalcogenides with NaBH4in PEG-400 as solvent and selectively added to electron-deficient alkenes. Chalcogenolate anions were directly added at mild conditions by this simple procedure and in all cases furnished the respective Michael adducts in short reaction times and good yields.
- Perin, Gelson,Borges, Elton L.,Peglow, Thiago J.,Lenard?o, Eder J.
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supporting information
p. 5652 - 5655
(2014/12/11)
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- Highly stereoselective anti-Markovnikov hydrothiolation of alkynes and electron-deficient alkenes by a supported Cu-NHC complex
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A practical, efficient, and low-cost heterogeneous catalyst consisting of a Cu-NHC (N-heterocyclic carbene) complex grafted to SBA-15 silica for the catalytic hydrothiolation of alkynes and electron-deficient alkenes under mild reaction conditions has been developed. The heterogeneous catalyst displays higher activity and stereoselectivity to Z-anti-Markovnikov isomers compared with the homogeneous analog under otherwise identical reaction conditions. The catalytic system is applicable to a broad range of alkynes and thiols and is recyclable without significant loss in catalytic performance. High activity and perfect selectivity to alkyl sulfides formed by the addition of electron-deficient alkenes to various thiols catalyzed by the supported Cu-NHC complex were also realized. This journal is the Partner Organisations 2014.
- Yang, Yong,Rioux, Robert M.
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p. 3916 - 3925
(2014/08/05)
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- Hybrid material from Zn[aminoacid]2 applied in the thio-Michael synthesis
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Recently, methodologies that are in accordance with green chemistry principles have been garnering increasing attention. One of the most applied methods in this field is heterogeneous catalysis. In this context, many catalysts have been developed, and the
- Darbem, Mariana P.,Oliveira, Aline R.,Winck, Cristiane R.,Rinaldi, Andrelson W.,Domingues, Nelson Luís C.
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p. 5179 - 5181
(2015/01/08)
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- Bifunctional acid-base ionic liquid for the one-pot synthesis of fine chemicals: Thioethers, 2H-chromenes and 2H-quinoline derivatives
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A bifunctional organocatalyst with ionic liquid properties and with an optimized distance between the acid and basic sites efficiently activates electron deficient olefins for 1,4 conjugated addition, which can be incorporated in different one-pot transformations for the preparation of cyclic and acyclic compounds of biological and synthetic interest. More specifically, the catalyst can be successfully applied for different carbon-carbon (CC) and carbon-heteroatom (C-N, C-O, C-S) bond forming reactions integrated in a cascade sequence. The activity of the organocatalyst has been compared with that of structurally related monofunctional and bifunctional catalysts. The most attractive features of this procedure are the high atom economy and the use of inexpensive starting materials as well as the use of an environmentally friendly catalyst that can be easily recovered due to its ionic liquid properties.
- Climent, Maria J.,Iborra, Sara,Sabater, Maria J.,Vidal, Juan D.
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- Mild hydrosulfenylation of Olefins under neutral conditions using a defined NHC-ligated iron-sulfur catalyst
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A defined NHC-Fe-S complex proved to be an efficient catalyst for the selective hydrosulfenylation of α,β-unsaturated ketones or vinylnitriles. A wide range of different aliphatic thiols were transferred in this atom-economic reaction into the correspondi
- Alt, Isabel,Rohse, Philipp,Plietker, Bernd
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p. 3002 - 3005
(2014/01/06)
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- Highly efficient proline ester-based nickel catalysts for Michael addition of thiophenols to α,β-enones
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Two N3O2 pentadentate ligands, BMPP and BPPP, were prepared for synthesizing highly efficient nickel catalysts, [Ni(BMPP)(CH 3CN)](ClO4)2 (1) and [Ni(BPPP)(CH 3CN)](BPh4)(ClO4) (2), for thia-Michael addition of thiophenols to α,β-enones. X-ray structures of 1 and 2 revealed that a labile CH3CN molecule was bound to the nickel center of the catalysts. ESI-MS spectroscopy indicated that thiolate replaced the bound CH3CN molecule and coordinated to the nickel center during the catalytic cycle.
- Lee, Way-Zen,Chiang, Chien-Wei,Kulkarni, Girish M.,Kuo, Ting-Shen
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p. 245 - 250
(2013/07/27)
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- Combined bead polymerization and Cinchona organocatalyst immobilization by thiol-ene addition
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In this work, we report an unusually concise immobilization of Cinchona organocatalysts using thiol-ene chemistry, in which catalyst immobilization and bead polymerization is combined in a single step. A solution of azo initiator, polyfunctional thiol, polyfunctional alkene and an unmodified Cinchona-derived organocatalyst in a solvent is suspended in water and copolymerized on heating by thiol-ene additions. The resultant spherical and gel-type polymer beads have been evaluated as organocatalysts in catalytic asymmetric transformations.
- Fredriksen, Kim A.,Kristensen, Tor E.,Hansen, Tore
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experimental part
p. 1126 - 1133
(2012/09/05)
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- Ionic liquid/PPh3 promoted cleavage of diphenyl disulfide and diselenide: A straight-forward metal-free one-pot route to the synthesis of unsymmetrical sulfides and selenides
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A metal-free cleavage of diphenyl disulfide and diphenyl diselenide has been achieved using ionic liquid/triphenyl phosphine (PPh3) and a convenient protocol for the one-pot synthesis of unsymmetrical sulfides and selenides by condensing 'in situ' generated thiolate or selenate anion with alkyl halides has been developed. In addition, 1,4-conjugate addition of the generated thiolate anions to activated alkenes has also been demonstrated. The ionic liquid, 1-methyl-3-pentyl imidazolium bromide, [pmIm]Br plays a crucial role in promoting the course of the reactions and shows superior activity and selectivity compared to other solvents. The [pmIm]Br has been reused for at least five times without appreciable loss of activity.
- Banerjee, Subhash,Adak, Laksmikanta,Ranu, Brindaban C.
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supporting information; experimental part
p. 2149 - 2152
(2012/05/05)
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- Acidic-functionalized ionic liquid as an efficient, green and reusable catalyst for hetero-Michael addition of nitrogen, sulfur and oxygen nucleophiles to α,β-unsaturated ketones
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A series of acidic-functionalized ionic liquids were synthesized and applied to the hetero-Michael addition of nitrogen, sulfur and oxygen nucleophiles to α,β-unsaturated ketones under solvent-free conditions. Notably, 1-methylimidazolium p-toluenesulfoni
- Han, Feng,Yang, Lei,Li, Zhen,Xia, Chungu
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experimental part
p. 346 - 354
(2012/01/14)
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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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- A bioinspired ZnII/FeIII heterobimetallic catalyst for thia-Michael addition
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A novel tetranuclear ZnII/FeIII heterobimetallic complex was synthesized, and the complex can efficiently catalyze the Michael addition of thiophenols to α,β-unsaturated enones, even for tertiary carbon-sulfur bond formation.
- Lee, Way-Zen,Wang, Tzu-Li,Chang, Hao-Ching,Chen, Yi-Ting,Kuo, Ting-Shen
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scheme or table
p. 4106 - 4109
(2012/07/14)
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- Stereoselective thio-Michael addition to chalcones in water catalyzed by bovine serum albumin
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A biomimetic, inexpensive, and simple method for the stereoselective thio-Michael addition of thiols to chalcones has been developed using bovine serum albumin (BSA) as a catalyst. Optically active products are obtained in high yield and with enantiomeric
- Gaggero, Nicoletta,Albanese, Domenico Carlo Maria,Celentano, Giuseppe,Banfi, Stefano,Aresi, Alice
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experimental part
p. 1231 - 1233
(2011/10/19)
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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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- 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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- Synthesis and application of modified silica sulfuric acid as a solid acid heterogeneous catalyst in Michael addition reactions
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Figure represented. Modified silica sulfuric acid (MSSA) as a new type of silica sulfuric acid was prepared and effectively used in the conjugate addition of indole, pyrrole, and thiols with Michael acceptors under mild conditions at room temperature. Als
- Zolfigol, Mohammad Ali,Veisi, Hojat,Mohanazadeh, Farajollah,Sedrpoushan, Alireza
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experimental part
p. 977 - 986
(2011/09/16)
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- Highly enantioselective organocatalytic sulfa-michael addition to α, β-unsaturated ketones
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"Chemical Equation Presented" A cinchona alkaloid-derived urea was found to be an efficient organocatalyst for catalyzing enantioselective conjugate addition between thiols and various α,β-unsaturated ketones to provide optically active sulfides with high
- Rana, Nirmal K.,Selvakumar, Sermadurai,Singh, Vinod K.
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supporting information; experimental part
p. 2089 - 2091
(2010/06/16)
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- Asymmetrie ruthenium-catalyzed 1,4-additions of aryl thiols to enones
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Well defined, stable, one-point binding ruthenium complexes 1 and 2 selectively bind and activate α,β-unsaturated carbonyl compounds for cycloaddition reactions. These mild Lewis acids catalyze asymmetric 1,4-addition reactions of aryl thiols to enones wi
- Badoiu, Andrei,Bernardinelli, Gerald,Besnard, Celine,Peter Kuendig
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supporting information; experimental part
p. 193 - 200
(2010/04/25)
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- DOSY NMR for monitoring self aggregation of bifunctional organocatalysts: Increasing enantioselectivity with decreasing catalyst concentration
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In this report, we demonstrate that self-aggregation is an intrinsic problem of bifunctional organocatalysts, especially in the case when the substrates do not have functional groups which are able to bind strongly with catalyst. Due to their self-associa
- Jang, Hyeong Bin,Rho, Ho Sik,Oh, Joong Suk,Nam, Eun Hye,Park, Sang Eun,Bae, Han Yong,Song, Choong Eui
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supporting information; experimental part
p. 3918 - 3922
(2010/09/17)
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- Improved design of inherently chiral calix[4]arenes as organocatalysts
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Improvement of the design of inherently chiral calix[4]arenes as organocatalysts was accomplished via the introduction of a diarylmethanol structure. Novel, inherently chiral calix[4]arenes bearing a tertiary amine or a quaternary ammonium moiety, togethe
- Shirakawa, Seiji,Shimizu, Shoichi
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experimental part
p. 1217 - 1222
(2010/08/08)
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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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- Silica nanoparticles as a reusable catalyst: A straightforward route for the synthesis of thioethers, thioesters, vinyl thioethers and thio-Michael adducts under neutral reaction conditions
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A simple and straightforward route for the synthesis of thioethers, thioesters, vinyl thioethers and thio-Michael adducts has been demonstrated using silica nanoparticles (NPs) as a reusable catalyst via the 1,2-addition of thiols to alkenes, alkynes and alkyl/acyl halides, and the 1,4-addition of thiols to conjugated alkenes at room temperature.
- Banerjee, Subhash,Das, Jayanta,Alvarez, Richard P.,Santra, Swadeshmukul
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experimental part
p. 302 - 306
(2010/06/13)
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- Supported cobalt complex-catalysed conjugate addition of indoles, amines and thiols to α,β-unsaturated compounds
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A highly active and reusable supported Co(ii) complex on SBA-15 shows an excellent activity and selectivity to target products in aza- and thia-Michael conjugate additions of indoles, amines and thiols to α,β-unsaturated compounds under solventless mild reaction conditions. The Co-catalyst was also highly reusable and comparably more active than related catalysts in the reaction.
- Rajabi, Fatemeh,Razavi, Sepideh,Luque, Rafael
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experimental part
p. 786 - 789
(2010/09/05)
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- Bioinspired catalytic conjugate additions of thiophenols to α,β-enones by a disubstituted benzoate-bridged nickel mimic for the active site of urease
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A disubstituted benzoate polydentate ligand, 2,6-bis[bis(pyridinyl-2- methyl)aminoethoxyl]benzoate (HL), was prepared to synthesize nickel mimics for the active site of urease. Reaction of the deprotonated L- with Ni(ClO4)2/sup
- Lee, Way-Zen,Tseng, Huan-Sheng,Wang, Tzu-Li,Tsai, Hui-Lien,Kuo, Ting-Shen
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scheme or table
p. 2874 - 2881
(2010/10/04)
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- Synthesis and resolution of a multifunctional inherently chiral calix[4]arene with an ABCD substitution pattern at the wide rim: The effect of a multifunctional structure in the organocatalyst on enantioselectivity in asymmetric reactions
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An efficient synthetic route to inherently chiral calix[4]arenes with an ABCD substitution pattern at the wide rim in the cone conformation was developed for the first time. For the synthesis of inherently chiral ABCD-type calix[4]arenes, first 5,11-dibro
- Shirakawa, Seiji,Kimura, Tomohiro,Murata, Shun-Ichi,Shimizu, Shoichi
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experimental part
p. 1288 - 1296
(2009/06/28)
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- Synthesis of an inherently chiral calix[4]arene amino acid and its derivatives: Their application to asymmetric reactions as organocatalysts
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The synthesis of an inherently chiral calix[4]arene amino acid as a chiral building block has been achieved in order for subsequent, transformation to various types of inherently chiral calix[4]arenes. The optically pure, inherently chiral calix[4]arene a
- Shirakawa, Seiji,Shimizu, Shoichi
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experimental part
p. 1916 - 1924
(2009/09/06)
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- Catalytic carbon-sulfur bond formation by amphoteric vanadyl triflate: exploring with thia-Michael addition, thioacetalization, and transthioacetalization reactions
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A series of thiols have been examined as protic nucleophiles for Michael-type additions to α,β-unsaturated carbonyls as well as double nucleophilic condensations with aldehydes, ketones, and acetals catalyzed by amphoteric, water-tolerant vanadyl triflate under mild and neutral conditions. The newly developed C-S bond formation protocols were carried out smoothly in good to high yields in a highly chemoselective manner.
- Chen, Chien-Tien,Lin, Yow-Dzer,Liu, Cheng-Yuan
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supporting information; experimental part
p. 10470 - 10476
(2010/02/28)
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- Synthesis, optical resolution and enantiomeric recognition ability of novel, inherently chiral calix[4]arenes: Trial application to asymmetric reactions as organocatalysts
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Newly designed, inherently chiral calix[4]arenes containing amino phenol structures have been synthesized and resolved to optically pure forms. The enantiomeric recognition ability of one chiral calix[4]arene was examined with mandelic acid by 1/sup
- Shirakawa, Seiji,Moriyama, Akihiro,Shimizu, Shoichi
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experimental part
p. 5957 - 5964
(2009/05/27)
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- Triethylammonium acetate (TEAA): A recyclable inexpensive ionic liquid promotes the chemoselective aza- and thia-Michael reactions
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A new, highly efficient, inexpensive, recyclable, mild, convenient, and green protocol for chemoselective aza/thia-Michael addition reactions of amines/thiols to α,β-unsaturated compounds using triethylammonium acetate (TEAA) ionic liquid was developed. The catalyst can be recycled ten times and obviate the need for toxic and expensive catalysts.
- Verma, Akhilesh K.,Attri, Pankaj,Chopra, Varun,Tiwari, Rakesh K.,Chandra, Ramesh
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experimental part
p. 1041 - 1047
(2009/11/30)
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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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- Efficient synthesis of β-alkyl/arylsulfanyl carbonyl compounds by In-TMSCl-promoted cleavage of dialkyl/diaryl disulfides and subsequent Michael addition
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A convenient and efficient procedure for the synthesis of β-alkyl/arylsulfanyl carbonyl compounds has been developed by a simple one-pot reaction of dialkyl/diaryl sulfides with α,β-unsaturated aldehydes, ketones, carboxylic esters, and nitriles in presence of indium and trimethylsilyl chloride under sonication. Copyright Taylor & Francis Group, LLC.
- Ranu, Brindaban C.,Mandal, Tanmay
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p. 1517 - 1523
(2008/02/03)
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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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- Solvent-free conjugated addition of thiols to citral using KF/alumina: preparation of 3-thioorganylcitronellals, potential antimicrobial agents
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A general, clean and easy method for the conjugated addition of thiols to citral promoted by KF/Al2O3 under solvent-free conditions at room temperature or under MW irradiation is described. It was found that the same protocol is appl
- Lenard?o, Eder J.,Ferreira, Patrícia C.,Jacob, Raquel G.,Perin, Gelson,Leite, Fábio P.L.
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p. 6763 - 6766
(2008/02/13)
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- Amino acid catalyzed thio-Michael addition reactions
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Using amino acid as a catalyst, an inexpensive, nontoxic, environmentally friendly, metal-free reaction procedure for C-S bond formation via thio-Michael addition reaction has been developed. The thio-Michael addition products were obtained in excellent yields under mild and neutral conditions. This metal-free catalytic protocol was found to be a good alternative to the existing metal catalyst methodology for the thio-Michael addition reaction.
- Kumar, Atul,Akanksha
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p. 11086 - 11092
(2008/02/12)
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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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- A simple, efficient, and green procedure for the 1,4-addition of thiols to conjugated alkenes and alkynes catalyzed by sodium acetate in aqueous medium
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A benign and inexpensive salt, sodium acetate, efficiently catalyzes 1,4-addition of thiols to a variety of conjugated alkenes such as ?,?-unsaturated ketones, aldehydes, carboxylic esters, nitriles, nitro compounds, and chalcones in aqueous THF. The reac
- Ranu, Brindaban C.,Mandal, Tanmay
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p. 223 - 227
(2008/02/10)
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- A kinetic study of the conjugate addition of benzenethiol to cyclic enones catalyzed by a nonsymmetrical uranyl-salophen complex
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(Chemical Equation Presented) The Et3N-assisted addition of benzenethiol to enones in chloroform is catalyzed with high turnover efficiency by the phenyl-substituted uranyl-salophen compound 3. Catalytic data show a close adherence to a quaterm
- Van Axel Castelli, Valeria,Dalla Cort, Antonella,Mandolini, Luigi,Pinto, Valentina,Schiaffino, Luca
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p. 5383 - 5386
(2008/02/10)
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- Indium(I) iodide promoted cleavage of dialkyl disulfides - Application of the Michael addition of thiolate anions to conjugated carbonyl compounds and regioselective ring opening of epoxides
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Indium(I) iodide promotes cleavage of dialkyl disulfides generating thiolate anions that then undergo facile addition to α,β-unsaturated ketones, aldehydes, carboxylic esters, and nitriles under neutral conditions producing corresponding β-ketosulfides or β-cyanosulfides. This strategy has also been used for the regioselective nucleophilic ring opening of epoxides by thiolate anions in presence of indium(III) chloride producing corresponding β-hydroxyphenyl sulfides. The reactions are in general, very clean, high yielding, and reasonably fast. Thus, simple and convenient procedures for the synthesis of β-ketosulfides or β-cyanosulfides and β-hydroxyalkyl sulfides have been developed using this cleavage reaction.
- Ranu, Brindaban C.,Mandal, Tanmay
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p. 762 - 770
(2007/10/03)
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- Formation of zinc thiolates by reductive cleavage of disulfides with the Zn/AlCl3 system in aqueous media, and their use for Michael addition
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A simple, convenient, and efficient one-pot protocol for the reductive cleavage of disulfides and Michael addition to α,β-unsaturated carbonyl compounds mediated by the Zn/AlCl3 system in aqueous media is reported.
- Movassagh, Barahman,Zakinezhad, Yousef
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- [HP(HNCH2CH2)3N]NO3: An efficient homogeneous and solid-supported promoter for aza and thia-Michael reactions and for Strecker reactions
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In the presence of a catalytic amount of an azaphosphatrane nitrate salt, amines and thiols react readily with Michael acceptors. The salt is also an efficient promoter for the one pot synthesis of α-amino and α-amidonitriles. By anchoring the salt to Merrifield Resin, a reusable heterogeneous catalyst is obtained for these reactions. Evidence is presented for catalysis being attributable solely to the NO3- ion.
- Fetterly, Brandon M.,Jana, Nirmal K.,Verkade, John G.
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p. 440 - 456
(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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- Perchloric acid impregnated on silica gel (HClO4/SiO 2): A versatile catalyst for Michael addition of thiols to the electron-deficient alkenes
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Perchloric acid adsorbed on silica gel (HClO4X/SiO2) has been found to be a highly efficient and versatile catalyst for the Michael addition of thiols to a wide variety of conjugated alkenes such as α,α-unsaturated ketones, carboxylic esters, nitriles, amides and chalcones in dichloromethane or methanol at room temperature. The reactions are completed within 2-20 min in high yields. Some of the additional advantages are: no aqueous work-up is necessary, and the catalyst is also reusable. Moreover, the solid product can be obtained without chromatographic separation. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
- Khan, Abu T.,Ghosh, Subrata,Choudhury, Lokman H.
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p. 2226 - 2231
(2007/10/03)
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