Chiral photochromism based on 6π-electrocyclization

Abstract

Photochromism involving chiral properties is important and interesting, particularly in the field of biological applications and liquid crystals. In this review, enantioselective and diastereoselective photochromic reactions based on thermally irreversible 6π-electrocyclizations are highlighted. Optical resolution of helical chirality of the hexatriene moiety can afford the enantiomers, however, racemization may occur. Diastereoselective photochromic reactions are more sophisticated and efforts to achieve high diastereoselectivity by us and others have been described.