Cobalt(II)-catalyzed stereospecific coupling of N-methylanilines with styreneoxides is developed via tandem C–N and C–O bond formation using tert-butyl hydroperoxide (TBHP) as an oxidant. Optically active epoxide can be reacted with high optical purity.
Functionalized enamines, including β-enaminoesters were synthesized using in situ generated HMDS amide bases via the combination of aminosilanes and fluoride salts.
Direct asymmetric aza Diels–Alder reaction catalyzed by chiral 2-pyrrolidinecarboxylic acid ionic liquid
作者:Xin Zheng、Yunbo Qian、Yongmei Wang
DOI:10.1016/j.catcom.2009.12.021
日期:2010.2
The utility of [EMIm][Pro] as an efficient catalyst for the one-pot direct asymmetric aza Diels–Alder reaction has been developed. A set of cyclic α,β-unsaturated ketones have been explored in up to 93% yield with up to >99/1 dr and >99% ee. Moreover, the catalytic system can be recycled and reused for six times without any significant loss of catalytic activity.
The enantioselective Bronsted acid catalyzed addition of methyleneaminopyrrolidine to N-Boc imines has been achieved in the presence of chiral phosphoric acids derived from 3,3'-di(phenanthryl)-H8-BINOL. The corresponding aminohydrazones have been isolated in good yields with enantiomeric excesses up to 90%.