KCS

Organostannanes are valuable intermediates in organic synthesis due to their versatility in C-C bond forming reactions. There are many methods for preparing vinylstannanes, among them the direct addition of tin-hydride to alkyne (hydrostannation) is the most attractive one in the view of efficiency and atom-economy. Numerous catalyst system based on transition metal-catalyzed syn-stereoselctive and radical initiator mediated anti-stereoslective hydrostannation has been developed, however controlling regio- and stereoselctivity are remained as a challenging task in the field of organic synthesis. Herein a novel catalyst system has developed for the hydrostannation of a range of alkynes with tributylstannane under mild conditions. The active catalytic species was formed from a stable dinucler complex under household fluoresecnt light (30 W) at room temperature. This ruthenium-catalyzed hydrostannation has shown a remarkable regio- and stereoselctivity for various internal and terminal alkynes. The regio- and stereoselectivity for the vinylstannanes resemble to those in radical-mediated hydrostannation, but has clear advantages in reaction efficiency over conventional ones using AIBN and BEt3, including the recyclability of the ruthenium catalyst.