title: Intermolecular asymmetric carboesterification of alkenes by using chiral amine auxiliaries under O2: synthesis of enantioenriched α-methylene-γ-lactones through chloropalladation of alkynes.
abstract: Herein, the first example of chloropalladation-initiated asymmetric intermolecular carboesterification of alkenes with alkynes by using chiral amine auxiliaries is reported. The use of (1S,2S)-N(1),N(1)-dimethylcyclohexane-1,2-diamine auxiliaries is essential for providing α-methylene-γ-lactones products in moderate to high yields and excellent enantioselectivities at room temperature. Moreover, the chiral amine auxiliaries can be readily removed by hydrolysis during the reaction process to keep the absolute configuration. This oxygen- and water-promoted asymmetric reaction opens a new window to study asymmetric processes in halopalladation reactions.
authors.affiliation: School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640 (P. R. China), Fax: (+86) 20-8711-2906.
authors.forename: Zhenming
authors.initials: Z
authors.lastname: Zhang
authors.forename: Wanqing
authors.initials: W
authors.lastname: Wu
authors.forename: Jianhua
authors.initials: J
authors.lastname: Liao
authors.forename: Jianxiao
authors.initials: J
authors.lastname: Li
authors.forename: Huanfeng
authors.initials: H
authors.lastname: Jiang
keywords: asymmetric synthesis; carboesterification; chiral auxiliary; chloropalladation; γ-lactones