Catalytic asymmetric Diels–Alder reactions of α-thioacrylates for the preparation of norbornenone
Abstract
CuII–bisoxazoline complexes catalyse the asymmetric Diels–Alder cycloaddition of α-thioacrylates with cyclopentadiene to give the cycloadducts in up to 92% yield, 88% de and >95% ee for the endo product; deprotection gives good yields of (1S,4S)-norbornenone with high enantioselectivity.