Takao Saito, Kayoko Takekawa and Tatsuhisa Takahashi
The catalytic, highly enantioselective hetero-Diels–Alder reactions of thiabutadienes using homochiral copper and nickel triflate and perchlorate bis(oxazoline) and bis(imine) complex catalysts to afford optically active dihydrothiopyrans are described for the first time.