- Modified poly(ε-caprolactone)s: An efficient and renewable access via thia-michael addition and Baeyer-Villiger oxidation
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The preparation of a novel class of ε-caprolactone (CL) monomers, modified at the β-position of the ester function, is described. The efficient thia-Michael addition to cyclohex-2-en-1-one and subsequent Baeyer-Villiger oxidation provided the regioselecti
- Winkler, Matthias,Raupp, Yasmin S.,Koehl, Lenz A.M.,Wagner, Hanna E.,Meier, Michael A.R.
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p. 2842 - 2846
(2014/06/09)
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- Novel atom-economic reaction: Comprehensive utilization of S-alkylisothiouronium salt in the synthesis of thioethers and guanidinium salts
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A novel atom-economic three-component one-pot reaction of a primary amine, an S-alkylisothiouronium salt and a Michael receptor is reported, which affords a guanidinium salt and thioether simultaneously. The guanidine moiety is involved in catalyzing the conjugated Michael addition of the mercaptan. The reaction proceeds under ambient conditions using a non-toxic EtOH-H2O mixture as the solvent, and the two products can be very easily purified. Complete atom economy is achieved by fully utilizing the S-alkylisothiouronium salt and converting the previously wasted mercaptan by-product into the valuable thioether.
- Gao, Pengchao,Leng, Penglin,Sun, Qi,Wang, Xin,Ge, Zemei,Li, Runtao
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p. 17150 - 17155
(2013/09/24)
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- Dolomite (CaMg(CO3)2) as a recyclable natural catalyst in Henry, Knoevenagel, and Michael reactions
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Iranian dolomite (CaMg(CO3)2) which consists of double-layered carbonates with Ca2+ and Mg2+ ions was utilized as a heterogeneous base catalyst in the CC, CN, and CS bond forming reactions via the Henry, Knoevenagel, aza-Michael, and thia-Michael transformations under mild conditions in water. Iranian dolomite has been characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Brunauer Emmett Teller (BET) and XRF chemical analysis, while its basic strength was evaluated by following the Hammett indicators procedure. This water-insoluble natural catalyst demonstrated high activity and was reusable.
- Tamaddon, Fatemeh,Tayefi, Mohammad,Hosseini, Elaheh,Zare, Elham
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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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- 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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- Pronounced catalytic effect of a micellar solution of sodium dodecyl sulfate (SDS) on the efficient C-S bond formation via an odorless thia-michael addition reaction through the in situ generation of S-alkylisothiouronium salts
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A pronounced catalytic effect of sodium dodecyl sulfate (SDS) was observed on the in situ production of 5-alkylisothiouronium salts via the reaction of primary, allyl and benzyl halides with thiourea in SDS droplets .Hydrolysis of the generated Salkylisot
- Firouzabadi, Habib,Iranpoor, Nasser,Abbasi, Mohammad
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experimental part
p. 755 - 766
(2009/11/30)
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- Hydrochalcogenation of activated olefines. Synthesis of functionalized dialkylchalcogenides
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Alkanethiols, selenols and tellurols are generated in situ by reaction of elemental sulfur, selenium and tellurium with commercial alkyllithiums, followed by reaction with deoxygenated water. The alkanechalcogenols react in situ with activated olefins in a Michael-type addition reaction.
- Comasseto, Jo?o V.,Gariani, Rogério A.,Princival, Jefferson L.,Dos Santos, Alcindo A.,Zinn, Fabiano K.
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p. 2929 - 2936
(2008/12/21)
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- In situ generation of n-butanethiol and its reaction with electron-deficient olefines
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n-Butanethiol is generated in situ by sequential addition of n-butyllithium and water to elemental sulfur. The n-butanethiol formed was reacted with electron-deficient olefines to give Michael-type addition products in good yields. The method avoids the manipulation of the bad-smelling n-butanethiol. Copyright Taylor & Francis Group, LLC.
- Gariani, Rogerio A.,Santos, Alcindo A. Dos,Comasseto, Joao V.
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p. 789 - 795
(2008/09/16)
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- Thia-Michael addition using cheap and odorless S-alkylisothiouronium salts as thiol equivalents in water
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S-Alkylisothiouronium salt has been found to be a non-toxic, odorless and simply operational alternative of thiol for the thia-Michael addition with electron-deficient olefins. The reactions were carried out under alkaline conditions in water at room temperature within 5-20 minutes to afford the expected products in good to excellent yields. Georg Thieme Verlag Stuttgart.
- Zhao, Yan,Ge, Ze-Mei,Cheng, Tie-Ming,Li, Run-Tao
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p. 1529 - 1532
(2008/02/04)
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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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- 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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- 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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- [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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- Potassium phosphate or silica sulfuric acid catalyzed conjugate addition of thiols to α,β-unsaturated ketones at room temperature under solvent-free conditions
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Potassium phosphate and silica sulfuric acid have been found to be useful and highly efficient catalysts for conjugate addition of thiols to α,β-unsaturated ketones under solvent-free conditions, at room temperature. Silica sulfuric acid (SSA) was found t
- Pore,Soudagar,Desai,Thopate,Wadagaonkar
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p. 9325 - 9328
(2007/10/03)
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- Indium(I) iodide-promoted cleavage of dialkyl disulfides and subsequent Michael addition of thiolate anions to conjugated carbonyl compounds
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Indium(I) iodide promotes cleavage of dialkyl disulfides generating thiolate anions which then undergo facile addition to α,β-unsaturated ketones, aldehydes, carboxylic esters and nitriles under neutral conditions producing corresponding β-keto or β-cyano
- Ranu, Brindaban C.,Mandal, Tanmay
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p. 1239 - 1242
(2007/10/03)
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- Catalysis by ionic liquid: A simple, green and efficient procedure for the Michael addition of thiols and thiophosphate to conjugated alkenes in ionic liquid, [pmIm]Br
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A room temperature ionic liquid, 1-pentyl-3-methylimidazolium bromide, [pmIm]Br efficiently catalyzes Michael addition of thiols and diethyl dithiophosphate to a variety of conjugated alkenes such as α,β- unsaturated carbonyl compounds, carboxylic esters,
- Ranu, Brindaban C.,Dey, Suvendu S.
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p. 4183 - 4188
(2007/10/03)
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- Bismuth nitrate-catalyzed versatile Michael reactions
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Bismuth nitrate-catalyzed versatile Michael reaction was developed to reduce the complications that characterize the current standard Michael reaction and used for facile preparation of organic compounds of widely different structures. For example, several substituted amines, imidazoles, thio compounds, indoles, and carbamates were prepared at room temperature by following this method. In contrast with the existing methods using many acidic catalysts, this method is very general, simple, high-yielding, environmentally friendly, and oxygen and moisture tolerant. However, the promoting role of bismuth nitrate in this reaction is not understood at this time.
- Srivastava, Neeta,Banik, Bimal K.
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p. 2109 - 2114
(2007/10/03)
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