Efficient and Regioselective Hydrosilylation of Alkynes to (<i>E</i>)‐β‐Vinylsilanes Using Dicobalt Complexes

ABSTRACT Three NNOPP [R‐C 5 H 3 N‐C 5 H 3 N‐COH‐(C 6 H 4 ‐PPh 2 ) 2 , L 1 : R = OCH 3 , L 2 : R = H, L 3 : R = CF 3 ] ligands are synthesized and introduced to cobalt centers. The corresponding dicobalt complexes[{R‐C 5 H 3 N‐C 5 H 3 N‐COH‐(C 6 H 4 ‐PPh 2 ) 2 }Co 2 Cl 3 ( 1 : R = OCH 3 , 2 : R = H, 3 : R = CF 3 )], which are bench‐stable, are developed, respectively. The regioselective hydrosilylations of terminal alkynes with primary silane are investigated to produce ( E )‐vinylsilanes in good yields with excellent regioselectivity, and complex 3 exhibits the highest activity.