Highly enantioselective reaction of alpha-selenoorganolithium compounds with chiral bis(oxazoline)s and preparation of enantioenriched benzylidencyclohexanes.

The enantioselective reaction of alpha-seleno carbanions derived from bis(phenylseleno)acetal and bis(2-pyridylseleno)acetal in the presence of bis(oxazoline)s with various electrophiles gave products with high enantioselectivity. The enantioselective reaction of alpha-lithio benzyl 2-pyridyl selenide gave the products with stereochemistry reverse to that obtained in the reaction of alpha-lithio benzyl phenyl selenide. Mechanistic investigation suggests the enantiodetermination of these reactions at -78 degrees C depends on dynamic thermodynamic resolution. The enantioselective reaction was applied to the preparation of enantioenriched olefins and epoxide.