179902-20-6Relevant articles and documents
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
