Regioselective hydrostannation of highly hindered arylalkynes under ortho-directing effects

Abstract Palladium-catalyzed hydrostannation reactions of ortho -disubstituted arylalkynes were achieved with total stereo- and regio-selectivity in THF at room temperature. The regioselectivity was found to be under the control of the ortho -substituents ( ortho -directing effects, ODE) and pure α-vinylstannanes are produced in good yields and as single isomers regardless of the substituents’ nature. These hydrostannation α-products are precursors of choice for the preparation of stereo-defined triarylolefins.