Radical Hydrostannylation, Pd(0)-Catalyzed Hydrostannylation, Stannylcupration of Propargyl Alcohols and Enynols: Regio- and Stereoselectivities

Different enynols and propargyl derivatives were sumitted to radical hydrostannylation (Bu 3 SnH/AIBN), Pd(0)-catalyzed hydrostannylation [Bu 3 SnH/Pd(0)], and stannylcupration [Bu 3 Sn(R)CuCNLi 2 ] conditions. Except for the radical stannylation reaction, high regio- and stereoselective formation of vinyl- and dienylstannanes are obtained. Results are tentatively explained in terms of steric Interactions between the alkyne or enyne substituents and the palladium or cuprate moieties in the different reaction intermediates.