title: Asymmetric organocatalytic cascade reaction of aldehydes with 2-amino-β-nitrostyrenes: synthesis of chiral tetrahydroquinolines and dihydroquinolines.
abstract: An organocatalytic enantioselective Michael addition/aza-cyclization cascade reaction of aldehydes with 2-amino-β-nitrostyrenes has been developed for the construction of fully substituted chiral tetrahydroquinolines. The reaction, promoted by diphenylprolinol TMS ether as an organocatalyst, generated the chiral tetrahydroquinolines in good to high yield with excellent diastereo- and enantioselectivities (up to >30:1 dr, >99% ee). The method also provided an alternative access to chiral 1,4-dihydroquinolines, which are difficult to synthesize by other methodologies.
authors.affiliation: Department of Chemistry, College of Natural Science, Kyonggi University , 154-42 Gwanggyosan-ro, Yeongtong-gu, Suwon 443-760, Republic of Korea.
authors.forename: Yona
authors.initials: Y
authors.lastname: Lee
authors.forename: Sung-Gon
authors.initials: SG
authors.lastname: Kim