179902-20-6Relevant academic research and scientific papers
Selective, green synthesis of six-membered cyclic carbonates by lipase-catalyzed chemospecific transesterification of diols with dimethyl carbonate
Pyo, Sang-Hyun,Hatti-Kaul, Rajni
, p. 797 - 802 (2012)
A facile and green synthesis of six-membered cyclic carbonates, the potential monomers for isocyanate-free polyurethanes and polycarbonates, was achieved by transesterification of diols with dimethyl carbonate catalyzed by immobilized Candida antarctica lipase B, Novozym435, followed by thermal cyclization in a solvent-free medium. The difference in the chemospecificity of the lipase for the primary, secondary and tertiary alcohols as acyl acceptors was utilized to obtain a highly chemoselective synthesis of the cyclic carbonate in high yield. In the lipase-catalyzed reaction with diols, the product contained almost equal proportions of mono- and di-carbonates with 1,3-propanediol having two primary alcohols, a higher proportion of mono-carbonate with 1,3-butanediol having a primary and a secondary alcohol, and mainly mono-carbonate with 3-methyl-1,3-butanediol having a primary and a tertiary alcohol. The chemospecificity of cyclic carbonates formed by thermal treatment at 90 °C was closely related to the proportion of mono-carbonate. The yield of cyclic carbonate was 99.3% with 3-methyl-1,3-butanediol, 85.5% with 1,3-butanediol, and 43.2% with 1,3-propanediol. Copyright
METHOD FOR PRODUCING CYCLIC CARBONATES
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Page/Page column 16, (2012/12/13)
Linear or cyclic carbonates as potential monomers for isocyanate-free polyurethanes and polycarbonates were prepared from polyols and dialkylcarbonatesor diphenyl carbonates. This invention was developed to produce linear or cyclic carbonates with or without using catalysts. Polyol compounds were reacted with carbonates such as dimethylcarbonate and diethylcarbonate to produce thecorresponding linear and/or cyclic carbonate.
