Metal Complex-Catalyzed Redistribution Reactions of Organsosilanes IV. Redistribution Reactions of Methylsiloxanes Catalyzed by Transition Metal Complexes

Redistribution reactions of a variety of hydrogen-substituted siloxanes are catalyzed by various transition metal complexes of iridium and rhodium. The products arise from breaking and remaking of Si-C, Si-H, and Si-0 bonds. Siloxanes not possessing a Si-H bond are inert under the conditions studied. The most favored reaction pathway appears to scramble preferentially the groups directly attached to the silicon bearing the hydrogen atom. A new cycle-iridiadisiloxane, L,(CO)(H)Ir(SiMeROSiMeR) (L = Ph,P; R = Me,SiO) is reported. This compound exists in three isomer-k forms as a consequence of the spatial arrangements of the R and Me groups on the ring