Efficient and convenient synthesis of β-vinyl sulfides in nickel-catalyzed regioselective addition of thiols to terminal alkynes under solvent-free conditions

A new nanosized catalytic system has been developed for convenient preparation of beta-vinyl sulfides H2C=C(SAr)R with high yields (79-98%) and excellent selectivity (> 98:2). Inexpensive and easily available Ni(acac)(2) was used as catalyst precursor. Solvent-free conditions were combined with high atom efficiency of the ArSH addition reaction to terminal alkynes (HC C-R) in order to create an environmentally friendly synthetic procedure. The mechanistic study has indicated that catalytic reaction takes place under heterogeneous conditions with alkyne insertion into the Ni-S bond as a key step.