One-pot organocatalytic asymmetric synthesis of 3-nitro-1,2-dihydroquinolines by a dual-activation protocol.
Generally, amine-catalyzed enantioselective transformations rely on chiral enamine or unsaturated iminium intermediates. Herein, we report a protocol involving dual activation by an aromatic iminium and hydrogen-bonding. An enantioselective aza-Michael-Henry domino reaction of 2-aminobenzaldehydes with nitroolefins has been developed through this protocol using primary amine thiourea catalysts to provide a variety of 3-nitro-1,2-dihydroquinolines in moderate yields and with up to 90% ee. The mechanism for the catalytic enantioselective reaction was confirmed by ESI mass spectrometric detection of the reaction intermediates. The products formed are substructures found in skeletons of important biological and pharmaceutical molecules.
Wang
Yi-Feng
YF
State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang University of Technology, Hangzhou 310014 (China), Fax: (+86) 0571-88320066.
Zhang
Wei
W
State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang University of Technology, Hangzhou 310014 (China), Fax: (+86) 0571-88320066.
Luo
Shu-Ping
SP
State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang University of Technology, Hangzhou 310014 (China), Fax: (+86) 0571-88320066.
Li
Bai-Lin
BL
State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang University of Technology, Hangzhou 310014 (China), Fax: (+86) 0571-88320066.|Department of Pharmaceutical and Chemical Engineering, Taizhou College, Linhai Zhejiang 317000 (China).
Xia
Ai-Bao
AB
State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang University of Technology, Hangzhou 310014 (China), Fax: (+86) 0571-88320066.
Zhong
Ai-Guo
AG
Department of Pharmaceutical and Chemical Engineering, Taizhou College, Linhai Zhejiang 317000 (China).
Xu
Dan-Qian
DQ
State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang University of Technology, Hangzhou 310014 (China), Fax: (+86) 0571-88320066.
D000588:Amines / Q000737:chemistry*; D001547:Benzaldehydes / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D004563:Electrochemistry; D006859:Hydrogen / Q000737:chemistry; D007477:Ions / Q000737:chemistry; D015394:Molecular Structure; D011804:Quinolines / Q000737:chemistry*; D013237:Stereoisomerism; D013890:Thiourea / Q000737:chemistry
D000588:Amines; D001547:Benzaldehydes; D007477:Ions; D011804:Quinolines; C000062:2-aminobenzaldehyde; D006859:Hydrogen; C037219:quinoline; D013890:Thiourea