Reaction mechanism study on reactions of phenylacetylenes with HSnEt₃promoted by B(C₆F₅)₃with and without DABCO

Abstract

There are great variety of transformations for phenylacetylenes. Most efforts have been focused on the dehydrogenative coupling, although nucleophilic addition is often observed as the side reaction. The selectivity of...

Palladium-catalyzed C(sp3)–Si cross-coupling silylation of benzyl halides with hydrosilanes

“…Second, the pre-coordination of palladium species A with hydrosilane occurs smoothly to give Pd complex B through a ternary transition state of the Si–H/Pd–Br bond, which is accelerated by B(C 6 F 5 ) 3 . 11,15 Third, activation of the Si–H bond is completed by transmetalation with the aid of an organic base to form silyl palladium complex C . The final step of reductive elimination of C results in the desired products 3 , and the regeneration of active Pd(0)/ligand species A takes place to re-coordinate with the substrate (benzyl halide) for the next catalytic cycle.…”