Organopalladium complex promoted asymmetric hetero Diels-Alder reactions between a thiocarbonyl dienophile and a phospha-substituted cyclic diene

摘要

The asymmetric [4 + 2] hetero cycloaddition reaction between methyl cyanodithioformate and 1-phenyl-3,4-dimethylphosphole has been achieved stereoselectively by use of the organopalladium(II) complex derived from (S)-N,N-dimethyl-1-(1-naphthylamine) as the chiral reaction template to produce the corresponding (+)-exo-syn-methylthio-substituted phosphanorbornene P-S bidentate chelate. The generation of the chelating cycloadduct involved an intramolecular cycloaddition mechanism in which both the cyclic diene and the hetero dienophile were coordinated simultaneously to the chiral palladium template during the course of the cycloaddition reaction. [References: 41]