The syntheses of carbon dioxide(CO_(2))based industrially important chemicals have gained considerable interest in view of the sustainable chemistry and“green chemistry”concepts.In this review,recent developments in...The syntheses of carbon dioxide(CO_(2))based industrially important chemicals have gained considerable interest in view of the sustainable chemistry and“green chemistry”concepts.In this review,recent developments in the chemical fixation of CO_(2)to valuable chemicals are discussed.The synthesis of five-member cyclic carbonates via,cycloaddition of CO_(2)to epoxides is one of the promising reactions replacing the existing poisonous phosgene-based synthetic route.This review focuses on the synthesis of cyclic carbonates,vinyl carbamates,and quinazoline-2,4(1H,3H)-diones via reaction of CO_(2)and epoxide,amines/phenyl acetylene,2-aminobenzinitrile and other chemicals.Direct synthesis of dimethyl carbonate,1,3-disubstituted urea and 2-oxazolidinones/2-imidazolidinones have limitations at present because of the reaction equilibrium and chemical inertness of CO_(2).The preferred alternatives for their synthesis like transesterification of ethylene carbonate with methanol,transamination of ethylene carbonate with primary amine and transamination reaction of ethylene carbonate with diamines/β-aminoalcohols are discussed.These methodologies offer marked improvements for greener chemical fixation of CO_(2)in to industrially important chemicals.展开更多
Environmentally benign one-pot protocol is used in the synthesis of silver nanoparticles （AgNPs） in powder form, involving the reduction of silver nitrate in the presence of fully hydrolyzed polyvinyl alcohol （PVA...Environmentally benign one-pot protocol is used in the synthesis of silver nanoparticles （AgNPs） in powder form, involving the reduction of silver nitrate in the presence of fully hydrolyzed polyvinyl alcohol （PVA） as stabilizer by hydrogen （H2） as reducing agent in aqueous medium. Fully hydrolyzed biodegradable PVA has extremely low cytotoxicity, making it a favorable stabilizer from green perspective. In the present methodology, essentially naked silver nanoparticles are obtained in good yield. The prepared sil- ver nanoparticles were characterized by TEM, XRD, EDAX, UV-Vis spectroscopy and DLS histogram, and studied for its activity as a recyclable catalyst for synthesis of different enaminones.展开更多
基金the All India Council for Technical Education(AICTE),India through Grant No.8023/BOR/RID/RPS-58/2008-09 for providing financial support for this work.
文摘The syntheses of carbon dioxide(CO_(2))based industrially important chemicals have gained considerable interest in view of the sustainable chemistry and“green chemistry”concepts.In this review,recent developments in the chemical fixation of CO_(2)to valuable chemicals are discussed.The synthesis of five-member cyclic carbonates via,cycloaddition of CO_(2)to epoxides is one of the promising reactions replacing the existing poisonous phosgene-based synthetic route.This review focuses on the synthesis of cyclic carbonates,vinyl carbamates,and quinazoline-2,4(1H,3H)-diones via reaction of CO_(2)and epoxide,amines/phenyl acetylene,2-aminobenzinitrile and other chemicals.Direct synthesis of dimethyl carbonate,1,3-disubstituted urea and 2-oxazolidinones/2-imidazolidinones have limitations at present because of the reaction equilibrium and chemical inertness of CO_(2).The preferred alternatives for their synthesis like transesterification of ethylene carbonate with methanol,transamination of ethylene carbonate with primary amine and transamination reaction of ethylene carbonate with diamines/β-aminoalcohols are discussed.These methodologies offer marked improvements for greener chemical fixation of CO_(2)in to industrially important chemicals.
基金The financial support from UGC-Green Technology CenterUniversity of Mumbai,India and collaborative support from DST-JSPS for Indo-Japan project no.DST/INT/JAP/P-67/08
文摘Environmentally benign one-pot protocol is used in the synthesis of silver nanoparticles （AgNPs） in powder form, involving the reduction of silver nitrate in the presence of fully hydrolyzed polyvinyl alcohol （PVA） as stabilizer by hydrogen （H2） as reducing agent in aqueous medium. Fully hydrolyzed biodegradable PVA has extremely low cytotoxicity, making it a favorable stabilizer from green perspective. In the present methodology, essentially naked silver nanoparticles are obtained in good yield. The prepared sil- ver nanoparticles were characterized by TEM, XRD, EDAX, UV-Vis spectroscopy and DLS histogram, and studied for its activity as a recyclable catalyst for synthesis of different enaminones.
