Copper-mediated regio- and enantio-selective cross-coupling of heterocyclic allyl sulphides with organomagnesium compounds: A case of 1,7-relative stereogenesis

Abstract

Optically active heterocyclic allyl sulphides 1–7 react with organomagnesium compounds in the presence of CuBr to afford optically active alkenes in good yields and very high γ-selectivity. The regioselectivity depends on the solvent as well on the CuBr: allylic sulphide ratio. The heterocyclic nucleus imparts asymmetric induction in the range of 50–98% ee. The regio- and enantio-selectivity of these reactions would be related to the coordination exerted by the heterocyclic nitrogen toward the copper organyl.