Direct catalytic asymmetric vinylogous Mannich-type and Michael reactions of an alpha,beta-unsaturated gamma-butyrolactam under dinuclear nickel catalysis.
Direct catalytic asymmetric vinylogous reactions of an alpha,beta-unsaturated gamma-butyrolactam as a donor are described. A homodinuclear Ni(2)-Schiff base complex promoted a vinylogous Mannich-type reaction of N-Boc imines as well as a vinylogous Michael reaction to nitroalkenes selectively at the gamma-position under simple proton-transfer conditions. Vinylogous Mannich adducts were obtained in 5:1-->30:1 dr and 99% ee, and vinylogous Michael adducts were obtained in 16:1-->30:1 dr and 93-99% ee.
Shepherd
Nicholas E
NE
Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Tanabe
Hirooki
H
Xu
Yingjie
Y
Matsunaga
Shigeki
S
Shibasaki
Masakatsu
M
D000475:Alkenes / Q000737:chemistry; D002384:Catalysis; D007769:Lactams / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D009532:Nickel / Q000737:chemistry*; D013237:Stereoisomerism
D000475:Alkenes; D007769:Lactams; D009532:Nickel