78843-65-9Relevant academic research and scientific papers
Catalytic asymmetric synthesis of diazabicyclo[3.1.0]hexanes by 1,3-dipolar cycloaddition of azomethine ylides with azirines
Adrio, Javier,Carretero, Juan C.,Díaz-Tendero, Sergio,Molina, Alba
supporting information, p. 5050 - 5053 (2020/05/18)
Substituted 1,3-diazabicyclo[3.1.0]hexanes with two contiguous quaternary stereocentres are readily prepared by catalytic asymmetric [3+2] cycloaddition of a-substituted iminoesters with azirines. High diastereoselectivities and enantioselectivities (up to 98% ee) are achieved using CuI/(R)-Fesulphos as the catalytic system.
Chemo-Enzymic Synthesis of Optically Active α,α-Disubstituted α-Amino Acids
Liu, Weiguo,Ray, Paul,Benezra, Steven A.
, p. 553 - 560 (2007/10/02)
A series of α,α-disubstituted α-amino esters was chemically synthesized and then resolved through enantioselective hydrolysis catalysed by a new enzyme isolated from crude Humicola langinosa lipase.This enzyme only accepts free amino esters as substrates with neither lipase activity toward olive oil nor esterase activity toward o-nitrophenyl butyrate.It is unique in that it successfully catalyses the resolution of amino esters with two large α-alkyl groups including aliphatic, aromatic and cyclic amino esters.Examples of resolutions where the alkyl groups differ in size by as little as a single carbon atom have been demonstrated.For determination of absolute configuration, some of the optically active α,α-disubstituted amino acids were also prepared through Schoellkopf's asymmetric synthesis and the structures were verified by X-ray crystallography.A model depicting the substrate binding site of the enzyme is proposed.
