Titanium(IV) Halide Mediated Coupling of Alkoxides and Alkynes: An Efficient and Stereoselective Route to Trisubstituted (E)-Alkenyl Halides

Alkoxide C-O bond cleavage occurs readily at room temperature in the presence of titanium(IV) halide. Capture of the resultant carbocation by alkynes provides an efficient route to trisubstituted (E)-alkenyl halides with high stereoselectivity.