title: Asymmetric phase-transfer catalysts bearing multiple hydrogen-bonding donors: highly efficient catalysts for enantio- and diastereoselective nitro-mannich reaction of amidosulfones.
abstract: Bifunctional asymmetric phase-transfer catalysts bearing multiple hydrogen-bonding donors have rarely been explored. The first quaternary ammonium type of these catalysts derived from cinchona alkaloids were readily prepared and found to be highly efficient catalysts for asymmetric nitro-Mannich reactions of amidosulfones. Compared with previous reports, very broad substrate generality was observed, and both enantiomers of the products were achieved in high enantio- and diastereoselectivity (90-99% ee, 13:1 to 99:1 dr).
authors.affiliation: Department of Organic Chemistry, College of Chemistry, Jilin University , 2699 Qianjin Street, Changchun 130012, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.forename: Yuxin
authors.initials: Y
authors.lastname: Liu
authors.forename: Cong
authors.initials: C
authors.lastname: Sun
authors.forename: Zhonglin
authors.initials: Z
authors.lastname: Wei
authors.forename: Jungang
authors.initials: J
authors.lastname: Cao
authors.forename: Dapeng
authors.initials: D
authors.lastname: Liang
authors.forename: Yingjie
authors.initials: Y
authors.lastname: Lin
authors.forename: Haifeng
authors.initials: H
authors.lastname: Duan