Activations of Silanes with [PhB(CH2PPh2)3]Ir(H)(η3-C8H13). Formation of Iridium Silylene Complexes via the Extrusion of Silylenes from Secondary Silanes R2SiH2

The abstraction of methide from (Me 3 P) 3 Ir(SiHMes 2 )(Me)(H) ( 1 ) with B(C 6 F 5 ) 3 gave the silylene complex [ fac -(Me 3 P) 3 (H) 2 Ir(SiMes 2 )][MeB(C 6 F 5 ) 3 ] ( 2 ) via 1,2-hydrogen migration. Secondary silanes (H 2 SiR 2 ) reacted with [PhBP 3 ]Ir(H)(η 3 -C 8 H 13 ) ( 3 ) (where [PhBP 3 ] = PhB(CH 2 PPh 2 ) 3 - ) to give silylene complexes of the type [PhBP 3 ](H) 2 Ir SiR 2 (R = 2,4,6-trimethylphenyl (Mes), 4a; R = Ph, 4b; R = Et, 4c; R = Me, 4d ), with loss of cyclooctene. Analogously, the germylene complex [PhBP 3 ](H) 2 Ir GeMes 2 was obtained via the reaction of 3 with Mes 2 GeH 2 . Primary silanes (H 3 SiR) reacted with 3 to give [PhBP 3 ](H) 2 Ir Si(R)( c- C 8 H 15 ) (R = Mes, 8a; R = 2,4,6-triisopropylphenyl (Trip), 8b ) via an intermediate silylene complex with an Si−H bond, [PhBP 3 ](H) 2 Ir Si(R)(H). With tertiary silanes (R 3 SiH), silyl-capped trihydride complexes of the type [PhBP 3 ]IrH 3 (SiR 3 ) (R = Et, 7a; R = Me, 7b ) and 1,3-cyclooctadiene were produced. The mechanisms of these processes are discussed.