title: Enantioselective preparation of cis-β-azidocyclopropane esters by cyclopropanation of azido alkenes using a chiral dirhodium catalyst.
abstract: A diastereo- and enantiocontrolled preparation of the conformationally restricted cis-β-azidocyclopropane esters have been developed. The Rh(2)(S-DOSP)(4) was found to be an efficient catalyst in hexane for the cyclopropanation of azido alkenes with diazo esters, and 19 cis-β-azidocyclopropane esters were prepared in excellent yields. The value of the diastereomer ratio was up to 99:1, and the enantiomeric excess was up to 95%. Furthermore, the relative and absolute configuration was confirmed by X-ray analysis.
authors.affiliation: Key Laboratory of Energy Sources & Engineering, and Department of Chemistry, Ningxia University, Yinchuan 750021, China. gupm@nxu.edu.cn
authors.forename: Peiming
authors.initials: P
authors.lastname: Gu
authors.forename: Yan
authors.initials: Y
authors.lastname: Su
authors.forename: Xiu-Ping
authors.initials: XP
authors.lastname: Wu
authors.forename: Jian
authors.initials: J
authors.lastname: Sun
authors.forename: Wanyi
authors.initials: W
authors.lastname: Liu
authors.forename: Ping
authors.initials: P
authors.lastname: Xue
authors.forename: Rui
authors.initials: R
authors.lastname: Li