S−H⋅⋅⋅π Driven Anti‐Markovnikov Thiol‐Yne Click Reaction

Herein we demonstrate that an anti-Markovnikov selective thiol-yne-click (TYC) reaction could be achieved between phenyl acetylenes and thiophenols by exploiting a newly identified S-H center dot center dot center dot pi non-covalent interaction without using any catalysts, additives and solvents. Natural bond orbital (NBO) analyses also supported that S-H center dot center dot center dot pi and cooperative pi-pi stacking interactions helped to promote this regioselective reaction. The hydrothiolated products were isolated in near quantitative yields. Also, the concept of self-sorting was demonstrated when styrene, phenyl acetylene and thiophenols were reacted in one pot. Owing to the stronger S-H center dot center dot center dot pi preference of ethynyl H over the vinyl = H hydrogen bond, selectively, TYC product formation was found to be dominating over the thiol-ene-click (TEC) product.