Expanding substrate scope of lipase-catalyzed transesterification by the utilization of liquid carbon dioxide
摘要:
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. (C) 2015 Elsevier Ltd. All rights reserved.
Mutant Lipase-Catalyzed Kinetic Resolution of Bulky Phenyl Alkyl<i>sec</i>-Alcohols: A Thermodynamic Analysis of Enantioselectivity
作者:Michaela Vallin、Per-Olof Syrén、Karl Hult
DOI:10.1002/cbic.200900635
日期:2010.2.15
Open to persuasion: The rationallydesigned, single point mutated variant, Candida antarcticalipaseB W104A, is a S‐selective catalyst for kinetic resolution of bulky phenyl alkyl alcohols. The catalyst's enantioselectivity differs within a homologous series of alcohols, depending on the different contributions from enthalpy and entropy.
Boron fluoride promoted opening of epoxides by organocopper and cuprate reagents
作者:A. Alexakis、D. Jachiet、J.F. Normant
DOI:10.1016/s0040-4020(01)88165-5
日期:1986.1
BF3 the reaction rate of organocopper and cuprate reagents with poorly reactive epoxides is dramatically enhanced. Lithium organocuprates are the best choice among the various organocopper and cuprate reagents tested. Even the dimesityl cyanocuprate is able to react with cyclohexeneoxide in excellent yield. No products of cationic rearrangements are observed. The reaction with variousepoxides shows
organocatalyst, graftpolymer supported dimethylaminopyridine (g‐DMAP), is developed. This catalyst has a flexible structure and comprises DMAP anchored to the polyethylene‐graft‐polyacrylic acid (PE‐g‐PAA). It exhibits higher activity than DMAP supported on polystyrene cross‐linked with divinylbenzene and can be recovered in batch mode acetylation. The activity and stability of this catalyst allow its application