α- and β-stannyl trifluoromethylbutenoates: Regioselective preparation and use in copper(I)-catalyzed allylation and propargylation reactions

Article abstract of DOI:10.1002/adsc.200900828

The palladium-free hydrostannylation of ethyl 4,4,4-trifluorobutynoate 1 with tributyltin hydride at room temperature is highly regio- and stereoselective, providing good yields of β-trifluoromethyl (Z)-a- or (Z)-β-stannylacrylates 2. Vinylstannanes 2 undergo a copper(I)-catalyzed coupling reactions with allylic or propargylic bromides leading selectively to good yields of the corresponding allylated or propargylated products without allylic or allenic transposition.