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
Natural quinones and their analogues have attracted growing attention because of their novel anticancer activities. A series of novel isothiazoloquinoline quinone analogues were synthesized and evaluated for antitumor activities against four different kind of cancer cells. Among them, isothiazoloquinolinoquinones inhibited cancer cells proliferation effectively with IC50 values in the nanomolar range