Ti-catalyzed regioselective ring-opening alkynylation of epoxides with haloalkynes

Ti-catalyzed ring-opening alkynylation of epoxides with haloalkynes has been achieved, allowing an efficient and regioselective entry to various propargylic alcohols in moderate to good yields. The developed protocol features extremely mild reaction conditions, broad substrate scope, varied functional group compatibility, and chemospecificity in the rearrangements of epoxides to aldehydes.