An Ethylene-Bridged Phosphane/Borane Frustrated Lewis Pair Featuring the -B(Fxyl)(2) Lewis Acid Component

摘要

Hydroboration of dimesitylvinylphosphane with bis[3,5-bis(trifluoromethyl) phenyl]borane [HB(Fxyl)(2)] gave the intramolecular ethylene-bridged P/B frustrated Lewis pair (FLP) Mes(2)PCH(2)CH(2)B(Fxyl)(2). The new compound underwent a variety of typical FLP reactions such as P/B-addition to the carbonyl group of p-chloro-benzaldehyde. Cooperative N,N-addition to nitric oxide gave the respective persistent P/B FLPNO center dot radical, which readily reacted with 1,4-cyclohexadiene by H-atom abstraction to yield the corresponding P/B FLPNOH product. The B(Fxyl)(2)-containing FLP reacted as a template for the HB(C6F5)(2) reduction of carbon monoxide to the formyl stage to give the respective FLP(eta(2)-formylborane) product. Most products were characterized by single-crystal X-ray crystal structure analysis.