Organocatalyzed asymmetric vinylogous Michael addition of α,β-unsaturated γ-butyrolactam
作者:Jinlong Zhang、Xihong Liu、Xiaojuan Ma、Rui Wang
DOI:10.1039/c3cc44059a
日期:——
Highly efficient asymmetric vinylogous 1,6-Michael addition of α,β-unsaturated γ-butyrolactam to 3-methyl-4-nitro-5-alkenyl-isoxazoles and Michael addition to trichloromethyl ketones by using a chiral quinine-derived squaramide organocatalyst were described, giving products with high diastereo- and enantioselectivities (up to >25â:â1 dr and 96% ee).
Organocatalytic Direct Asymmetric Vinylogous Michael Reaction of an α,β-Unsaturated γ-Butyrolactam with Enones
作者:Yong Zhang、Yong-Liang Shao、Hai-Sen Xu、Wei Wang
DOI:10.1021/jo102223v
日期:2011.3.4
An organocatalytic asymmetric directvinylogousMichaeladdition of α,β-unsaturated γ-butyrolactam to enones has been achieved with a simple bifunctional thiourea-tertiary amine catalyst, affording the γ-substituted butyrolactam products with high diastereo- and enantioselectivity (up to >40:1 dr and 94−99% ee).