Methanol assisted selective formation of 1,2-glycerol carbonate from glycerol and carbon dioxide using nBu2SnO as a catalyst

Selectively 1,2-glycerol carbonate was obtained from glycerol and carbon dioxide in methanol using 1 mol% (Bu2SnO)-Bu-n (dibutyltin(IV)oxide, 1) as a catalyst. The reaction attained equilibrium in 4 h and the yield of 1,2-glycerol carbonate obtained was as high as 35%. We observed the rate of the reaction depends oil the amount of the catalyst and methanol used. During the reaction We Could trap the intermediates and identify it by C-13 NMR, IR and mass spectrum of the reaction mixture. The reaction proceeds upon activation of 1 by methanol forming dibutyltindimethoxide followed by dibutyltinglycerate which undergoes CO2 insertion to produce non-isolable 7-membered tin-glycerolcarbonato complex that finally yield glycerol carbonate. Catalyst 1 was found to be successful even with 1,2-propanediol and ethylene glycol yielding the corresponding cyclic carbonate. (C) 2009 Elsevier B.V. All rights reserved.