Diverse Reactions of o -Carborane-Fused Silylenes with C≡E (E = C, P) Triple Bonds.

The reactivities of o -carborane-fused silylenes toward molecules with C≡E (E = C, P) bonds are reported. The reactions of bis(silylene) [(LSi:)C] 2 B 10 H 10 ( 1a , L = PhC(N t Bu) 2 ) with arylalkynes afforded bis(silylium) carborane adducts 2 and 3 , showing a Si(μ-C 2 )Si structure with an open-cage nido -carborane backbone. In contrast, the reaction of 1a with a phosphaalkyne AdC≡P (Ad = 1-adamantyl) smoothly furnished compound 4 , comprising fused CPSi rings with a C=Si double bond and Si-Si single bond, and the related formation mechanism was investigated by DFT calculations. Furthermore, when monosilylene [(LSi:)C]CHB 10 H 10 ( 1b ) was employed to react with AdC≡P, compound 5 was isolated. The structure of 5 features a 1,2,3-triphosphetene core. All products were characterized by NMR spectroscopy and/or X-ray crystallography.