Quinine-catalyzed enantioselective tandem conjugate addition/intramolecular cyclization of malononitrile and 1,4-dien-3-ones
作者:Zhi-Peng Hu、Jian Li、Xiao-Gang Yin、Xue-Jing Zhang、Ming Yan
DOI:10.3998/ark.5550190.0014.301
日期:——
An organocatalytic tandemconjugateaddition / intramolecularcyclization of malononitrile and conformationally restricted 1,4-dien-3-ones has been developed. A series of cinchona alkaloids and their derivatives were examined as the catalysts. Quinine was found to be the most efficient catalyst in the absence of any additive. The reaction gave 2-amino-4H-pyrans with high yield and excellent enantiopurity
Organocatalytic Conjugate Addition of Malononitrile to Conformationally Restricted Dienones
作者:Zhi-Peng Hu、Chun-Liang Lou、Jin-Jia Wang、Chun-Xia Chen、Ming Yan
DOI:10.1021/jo200112r
日期:2011.5.20
Organocatalytic conjugateaddition of malononitrile to conformationally restricted dienones has been studied. A series of chiral primary and tertiary amine catalysts were screened. A piperidine-based thiourea-tertiary amine was found to be the efficient catalyst. Chiral pyran derivatives were obtained in excellent yields and enantioselectivities via a cascade conjugate addition–intramolecular cyclization pathway