Ruthenium‐Catalyzed Heck‐Type Regioselective Benzylation of Terminal Alkynes via the Cleavage of Carbon‐Carbon Triple Bond

Comprehensive Summary An innovative and highly regioselective strategy has been developed for synthesizing Heck‐type products of ( E )‐ and ( Z )‐prop‐1‐ene‐1,3‐diyldiaryls by benzylation of alkynes through cleaving the carbon‐carbon triple bond of terminal alkynes. This method involves using a functionalized heterogeneous ruthenium‐chitosan based catalyst, which can be easily recycled by filtering and washing with solvent post‐reaction. By adopting this approach, the need for highly toxic alkyl halides, oxidants, and activation reagents is eliminated, while ensuring excellent E / Z selectivity in the formation of desired Heck‐type benzylation products in satisfactory yields. To further investigate the reaction mechanism, comprehensive step‐by‐step control experiments and DFT calculations were conducted, shedding light on potential implications for the synthesis of biologically active ( Z )‐ and ( E )‐prop‐1‐ene‐1,3‐diyldiarenes.