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دسترسی آزاد مقاله
1 - Baker’s yeast catalyzed Henry reaction: Biocatalytic C-C bond formation
Prabhakar Shrivas Nitesh Punyapreddiwar Atul Wankhade Sangesh Zodape Umesh PratapThe C-C bond formation is an important reaction in organic synthesis to obtain value-added intermediates. Therefore, in this paper an attempt has been made to accelerate the Henry reaction (C-C bond formation) between aryl aldehydes and nitromethane using less expensive چکیده کاملThe C-C bond formation is an important reaction in organic synthesis to obtain value-added intermediates. Therefore, in this paper an attempt has been made to accelerate the Henry reaction (C-C bond formation) between aryl aldehydes and nitromethane using less expensive whole cell biocatalyst, baker’s yeast (BY). The scope of the methodology was also tested for the heteryl aldehyde i.e. 2-chloro-3-formyl quinoline to obtain the corresponding quinoline containing nitroalcohol. The developed protocol is highly efficient and completely environmentally friendly. The work addressed the issue of non-aqueous biocatalysis, since Henry reaction catalysed by baker's yeast has been carried out in ethanol. پرونده مقاله -
دسترسی آزاد مقاله
2 - Regioselective conversion of epoxides to vicinal nitrohydrins catalyzed by silica-bound 3-{2-[poly(ethylene glycol)]ethyl}-substituted 1-methyl-1H-imidazol-3-ium bromide as a green and reusable catalyst under aqueous thermal conditions
Neda Ayashi Mehdi Fallah-Mehrjardi Ali Reza KiasatAn environmentally benign procedure for the synthesis of vicinal nitrohydrins via the regioselective ring opening reaction of epoxides with nitrite anion using silica-bound 3-{2-[poly(ethylene glycol)]ethyl}-substituted 1-methyl-1H-imidazol-3-ium bromide as an effective چکیده کاملAn environmentally benign procedure for the synthesis of vicinal nitrohydrins via the regioselective ring opening reaction of epoxides with nitrite anion using silica-bound 3-{2-[poly(ethylene glycol)]ethyl}-substituted 1-methyl-1H-imidazol-3-ium bromide as an effective heterogeneous phase transfer catalyst was described. Short reaction time, high yield of products, simple work-up procedure, and recyclability of the catalyst were some of the striking features of the present protocol. The recovered catalyst could be reused five times without any loss in its catalytic activity and selectivity. پرونده مقاله -
دسترسی آزاد مقاله
3 - N,N-Dimethylbiguanide immobilized on mesoporous and magnetically separable silica: Highly selective and feasible organocatalyst for synthesis of β-nitroalcohols
Gisya Abdi Abdolhamid Alizadeh Mohammad Khodaei Mustaffa Shamsuddin Sohrab Ghouzivand Mitra Fakhari Mojtaba Beygzadeh Amirhossein FallahAn organosuperbase (N,N-dimethylbiguanide) immobilized on mesoporous and magnetically separable silica supports, was found for the first time, to act as a highly-stable, scalable and efficient heterogeneous catalyst for the Henry reaction under mild and neutral conditio چکیده کاملAn organosuperbase (N,N-dimethylbiguanide) immobilized on mesoporous and magnetically separable silica supports, was found for the first time, to act as a highly-stable, scalable and efficient heterogeneous catalyst for the Henry reaction under mild and neutral condition. Several factors such as catalyst amount, solvent and reaction time concerning the reactivity were also discussed. The procedure constitutes the first immobilized biguanide promotion of selective synthesis of β-nitroalcohols without addition of stoichiometric amount of any base and showed a broad substrate scope. The uniqueness of this catalyst lay in its cleanness, cost-effectiveness, ease in removal at the end of reaction, and chemoselective formation of a wide range of β-nitroalcohols. These materials can be easily converted to other useful synthetic intermediates which many of them have been exemplified in synthetic organic chemistry and pharmaceutical industry. پرونده مقاله