91458-95-6Relevant articles and documents
Catalysis of hydrosilylation: Part XXXIV. High catalytic efficiency of the nickel equivalent of Karstedt catalyst [{Ni(η-CH2=CHSiMe2)2O} 2{μ-(η-CH2=CHSiMe2)2O}]
Maciejewski,Marciniec,Kownacki
, p. 175 - 181 (2007/10/03)
The nickel equivalent of Karstedt catalyst [{Ni(η-CH2=CHSiMe2)2O} 2{μ-(η-CH2=CHSiMe2)2O}] (1) appeared to be a very efficient catalyst for dehydrogenative coupling of vinyl derivatives (styrene, vinylsilanes, vinylsiloxanes) with trisubstituted silanes HSi(OEt)3, HSiMe2Ph. The reaction occurs via three pathways of dehydrogenative coupling, involving formation of an unsaturated compound as the main product as well as a hydrogenated olefin (DS-1) pathway, hydrogenated dimeric olefin (DS-2) and dihydrogen (DC), respectively. The reaction is accompanied by side hydrosilylation. Stoichiometric reactions of 1 with styrene and triethoxysilane, in particular synthesis of the bis(triethoxysilyl) (divinyltetramethyldisiloxane) nickel complex 3 and the first documented insertion of olefin (styrene) into Ni-Si bond of complex 3, as well as all catalytic data have allowed us to propose a scheme of catalysis of this complex reaction by 1.
Catalysis of hydrosilylation. XX. Unusual reaction of vinyltriethoxysilane with triethoxysilane catalyzed by nickel acetylacetonate
Marciniec, Bogdan,Maciejewski, Hieronim,Mirecki, Janusz
, p. 61 - 67 (2007/10/02)
Nickel acetylacetonate is shown to be a catalyst of an unusual reaction of vinyltriethoxysilane with triethoxysilane involving formation of bis(silyl)ethene and bis(silyl)butanes as the main products accompanied by others of direct and dehydrogenative hydrosilylation, bis(silyl)ethane and ethylsilane as well as products of redistribution of triethoxysilane and formation of oligomers.The latter reaction is a consequence of consecutive oligomerization of bis(silyl)ethenes and other products.The effect of temperature, the concentration ratio of substrates and the catalyst, and other reaction conditions on the conversion and reaction yield led us to propose a scheme explaining the course of this competitive-consecutive reaction.
