Synthesis and double-silylation reactions of a P2PtSi2 complex containing an o-carboranylene

The reaction of the 1,2-bis(dimethylsilyl)carborane 1 with Pt(CH2 = CH2)(PPh3) yielded the cyclic bis(silyl)platinum complex 2, which was found to be a good precursor for the double-silylation reaction. Thus, the reaction of 2 with RC=CR' in refluxing toluene yielded the six-membered disilyl ring compounds B10H10C2(SiMe2)(2)(RC = CR') (R = Ph, R' = Ph (3); R = Ph, R' = H (4); R = Et, R' = Et (5); R = Me, R' = Me (6); R = CO2Me, R' = CO2Me (7)). In contrast, the reaction of 1 with 1-hexyne under the same reaction conditions yielded the five-membered disilyl ring compound B10H10C2(SiMe2)(2)(C = C(C4H9)H) (8). Thermolysis of 2 with trans-cinnamaldehyde afforded the insertion compound 9, formed through the di-insertion of two carbonyl ligands into the C-Si bond of 2. The structure of the nine-membered-ring compound 9 was determined by single-crystal X-ray crystallography. The reaction of 2 with fumaronitrile yielded the cyclization product 14, which contains two types of disilyl moieties, an imino and an N,N-bis(silyl)amino group.