Novel thiourea-amine bifunctional catalysts for asymmetric conjugate addition of ketones/aldehydes to nitroalkenes: rational structural combination for high catalytic efficiency.
A series of thiourea-amine bifunctional catalysts have been developed by a rational combination of prolines with cinchona alkaloids, which are connected by a thiourea motif. The catalyst 3a, prepared from L-proline and cinchonidine, was found to be a highly efficient catalyst for the conjugate addition of ketones/aldehydes to a wide range of nitroalkenes (up to 98/2 dr and 96% ee). The privileged cinchonidine backbone and the thiourea motif are essential to the reaction activity and enantioselectivity.
Chen
Jia-Rong
JR
Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, 152 Luoyu Road, Wuhan, Hubei 430079, China. jrchen@mails.ccnu.edu.cn
Cao
Yi-Ju
YJ
Zou
You-Quan
YQ
Tan
Fen
F
Fu
Liang
L
Zhu
Xiao-Yu
XY
Xiao
Wen-Jing
WJ
D000447:Aldehydes / Q000737:chemistry*; D000475:Alkenes / Q000737:chemistry*; D000588:Amines / Q000737:chemistry*; D002384:Catalysis; D002930:Cinchona Alkaloids / Q000737:chemistry; D003432:Cross-Linking Reagents / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D011392:Proline / Q000737:chemistry; D013890:Thiourea / Q000737:chemistry*
D000447:Aldehydes; D000475:Alkenes; D000588:Amines; D002930:Cinchona Alkaloids; D003432:Cross-Linking Reagents; D007659:Ketones; D011392:Proline; D013890:Thiourea