title: Asymmetric cyclopropanation catalyzed by a series of copper-(Schiff-base) complexes with two chiral centers.
abstract: A series of copper(Schiff-base) complexes with two chiral centers derived from 1,2-diphenyl-2-amino-ethanol were synthesized and applied to catalyze the asymmetric cyclopropanation of ethenes with diazoacetates. A mechanism that can explain the observed results was proposed. Some of these complexes were also efficient catalysts for asymmetric cyclopropanation of 1,1-diphenylethene with ethyl diazoacetate, affording high e.e. of up to 98.6%. An e.e. of 80.7% was achieved when no solvent was used.
authors.affiliation: Department of Chemistry, University of Science and Technology of China, Hefei 230026, People's Republic of China.
authors.forename: Changsheng
authors.initials: C
authors.lastname: Jiang
authors.forename: Zhang
authors.initials: Z
authors.lastname: Ming
authors.forename: Qitao
authors.initials: Q
authors.lastname: Tan
authors.forename: Dai
authors.initials: D
authors.lastname: Qian
authors.forename: Tianpa
authors.initials: T
authors.lastname: You