Ruthenium-Catalyzed Silylation of Ethylene by Disilanes

Abstract

The bis(dihydrogen) ruthenium complex RuH2(H2)2(PCy3)2 (1) and the ethylene complex RuΗ(C2Η4)[P(η3-C6H8)Cy2](PCy3) (2), obtained by addition of ethylene to 1, catalyze efficiently the silylation of ethylene with HSiMe2SiMe2H (I) and with the series of disilanes HSiMe2(CH2)nSiMe2H (n = 2, II; n = 3, III; n = 4, IV). Reaction of I with ethylene produces the monosilanes (CH2CH)SiMe2(CH2CH3) (I.b) and (CH3CH2)SiMe2(CH2CH3) (I.c) resulting from the cleavage of the Si−Si bond and the functionalization of the Si−H bonds. For II−IV, three processes, hydrosilylation, dehydrogenative silylation, and cyclization, are in competition, leading to the formation of acyclic monofunctionalized intermediates HSiMe2(CH2)nSiMe2(CHCH2) (II.f−IV.f) and HSiMe2(CH2)nSiMe2(CH2CH3) (II.g−IV.g), acyclic difunctionalized compounds (CH2CH)SiMe2(CH2)nSiMe2(CHCH2) (II.a−IV.a), (CH2CH)SiMe2(CH2)nSiMe2(CH2CH3) (II.b−IV.b), and (CH2CH3)SiMe2(CH2)nSiMe2(CH2CH3) (II.c−IV.c), together with cyclic products [(SiMe2)(CH2)3(SiMe2)](CHCH2) (II.d−I...