Fe-Promoted Chlorobenzylation of Terminal Alkynes through Benzylic C(sp(3))-H Bond Functionalization.

A chlorobenzylation of terminal alkynes through Fe(II)-promoted benzylic C(sp(3))-H bond functionalization in the presence of NCS as a chloride source was developed. Compared with previous methods to prepare polysubstituted alkenyl halides, the presented procedure provides an efficient alternative with high atom and step economy under mild conditions. The transformation was established to proceed through a single-electron transfer (SET) process with benzyl cations as key intermediates.