777-80-0Relevant academic research and scientific papers
Thiol-ene grafting from polylactic acid, polycaprolactone, and polyhydroxybutyrate
Belkhir, Kedafi,Jegat, Corinne,Taha, Mohamed
, p. 82 - 89 (2016)
Thiol-ene additions of different monomers from multi-thiol functionalized biodegradable polymers are analyzed in this study. These monomers include quaternary ammonium groups known for their biological activities; and also methyl methacrylate (MMA) and hydroxyethyl methacrylate (HEMA), which are used to control the hydrophilic-hydrophobic balance in the issued copolymers. Monomer conversion and the resulting polymer structures are confirmed principally by 1H nuclear magnetic resonance (NMR) spectra. Model reactions are first conducted with thiophenol, and then polylactic acid (PLA), polycaprolactone (PCL), and polyhydroxybutyrate (PHB) multi-thiol functionalized polymers are successfully used. The structures of the obtained products are analyzed by 1H NMR spectra: all the reactions are kinetically controlled and monomer additions are controllable. Chain transfer constants of the used monomers to the multi-thiol functionalized PLA are between 1.4 and 1.9. The obtained products were also characterized by size-exclusion chromatography (SEC), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA).
Facile Thiol–Ene Click Protocol Using Benzil as Sensitizer and White LED as Light Source
Das, Anupam,Thomas, K. R. Justin
supporting information, p. 7214 - 7218 (2020/11/30)
The thiol–ene reaction leading to a series of thioether derivatives by simple metal and oxidant free visible light promoted photosensitized protocol, following anti-Markonikov hydrothiolation of unactivated aryl and alkyl olefins at room temperature is demonstrated. Benzil served as a green photosensitizer in this reaction and white LED lights as a light source. This radical based thiol–ene reaction is operationally simple and tolerates a wide variety of functional groups present in olefins.
The Effect of Viscosity on the Diffusion and Termination Reaction of Organic Radical Pairs
Li, Xiaopei,Ogihara, Tasuku,Abe, Manabu,Nakamura, Yasuyuki,Yamago, Shigeru
, p. 9846 - 9850 (2019/07/10)
The effect of viscosity on the diffusion efficiency (Fdif) of an organic radical pair in a solvent cage and the termination mechanism, that is, the selectivity of disproportionation (Disp) and combination (Comb) of the geminated caged radical pair and the diffused radicals encountered, were investigated quantitatively by following the photolysis of dimethyl 2,2′-azobis(2-methylpropionate) (V-601) in the absence and presence of PhSD. Fdif and Disp/Comb selectivity outside the cage [Disp(dif)/Comb(dif)] are highly sensitive to the viscosity. In contrast, the Disp/Comb selectivity inside the cage [Disp(cage)/Comb(cage)] is rather insensitive. The difference in viscosity dependence between Disp(cage)/Comb(cage) and Disp(dif)/Comb(dif) is explained by the spin state of the radical pair inside and outside the cage and the spin state dependent configurational changes of the radical pair upon their collision. Given that the configurational change of the radicals associates the displacement and reorganization of solvents around the radicals, the termination outside the cage, which requires larger change than that inside the cage, is highly viscosity dependent. Furthermore, while the bulk viscosity of each solvent shows good correlation with Fdif and Disp/Comb selectivity, microviscosity is the better parameter predicting Fdif and Disp(dif)/Comb(dif) selectivity regardless of the solvents.
Stereoselective total synthesis of (-)-nupharamine utilizing an α-chlorosulfide and a sulfinimine for C-C bond formation
Raghavan, Sadagopan,Rajendar, Sheelamanthula
, p. 131 - 137 (2015/12/30)
An efficient stereoselective synthesis of the nuphar alkaloid, (-)-nupharamine, is reported. The key features include the Lewis acid catalyzed reaction of an α-chlorosulfide with a silyl ketene acetal for C-C bond formation, creation of the stereocenter at C2 by a diastereoselective reaction of allyl indium with a sulfinimine and reductive amination for the introduction of the C6 stereocenter of the piperidine ring.
Supported cobalt complex-catalysed conjugate addition of indoles, amines and thiols to α,β-unsaturated compounds
Rajabi, Fatemeh,Razavi, Sepideh,Luque, Rafael
experimental part, p. 786 - 789 (2010/09/05)
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.
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
Guo, Wenxue,Lv, Guangshu,Chen, Jiuxi,Gao, Wenxia,Ding, Jinchang,Wu, Huayue
supporting information; experimental part, p. 2297 - 2300 (2010/06/16)
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.
Borax as an efficient metal-free catalyst for hetero-Michael reactions in an aqueous medium
Hussain, Sahid,Bharadwaj, Saitanya K.,Chaudhuri, Mihir K.,Kalita, Harjyoti
, p. 374 - 378 (2007/10/03)
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.
Efficient synthesis of β-alkyl/arylsulfanyl carbonyl compounds by In-TMSCl-promoted cleavage of dialkyl/diaryl disulfides and subsequent Michael addition
Ranu, Brindaban C.,Mandal, Tanmay
, p. 1517 - 1523 (2008/02/03)
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.
Perchloric acid impregnated on silica gel (HClO4/SiO 2): A versatile catalyst for Michael addition of thiols to the electron-deficient alkenes
Khan, Abu T.,Ghosh, Subrata,Choudhury, Lokman H.
, p. 2226 - 2231 (2007/10/03)
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.
The iron(III) chloride-mediated 1,4-addition of mercaptans to α,β-unsaturated ketones and esters under solvent free conditions
Chu, Cheng-Ming,Huang, Wan-Ju,Lu, Chaowei,Wu, Pohsi,Liu, Ju-Tsung,Yao, Ching-Fa
, p. 7375 - 7380 (2007/10/03)
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.
