Expanding substrate scope of lipase-catalyzed transesterification by the utilization of liquid carbon dioxide

Secondary alcohols having bulky substituents on both sides of the chiral center are often poor substrates for most lipases. Here we reported that substrate scopes of two of the most used lipases, Candida antarctica lipase B and Burkholderia cepacia lipase, were found to be expanded toward more bulky secondary alcohols such as 1-phenyl-1-dodecanol and 2-methyl-1-phenyl-1-propanol by simply using them in liquid carbon dioxide as a solvent. The effects of solvents, reaction pressure, and pre-treatment of the enzyme with liquid CO2 on this acceleration phenomenon were also studied.