Carbon dioxide:a renewable feedstock for the synthesis of fine and bulk chemicals

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.