Catalytic activity of silyloxy-rhodium(I) complexes in hydrosilylation of alkenes

• Published in: Journal of molecular catalysis. A, Chemical Vol. 144; no. 2; pp. 263 - 271
• Main Authors: Marciniec, Bogdan, Krzyżanowski, Piotr, Walczuk-Guściora, Edyta, Duczmal, Wojciech
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 05.07.1999; Elsevier
• Subjects: Catalysis; Chemistry; Exact sciences and technology; General and physical chemistry; Hydrosilylation; Molecular catalysis; Siloxy-rhodium complexes; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Hydrosilylation; Molecular catalysis; Siloxy-rhodium complexes; Rhodium complex; Hexene; Concentration effect; Organic ligand; Platinoid Complexes; Transition metal Complexes; Kinetic parameter; Silyl complex; Experimental study; Catalyst activity; Catalyst
• ISSN: 1381-1169; 1873-314X
• DOI: 10.1016/S1381-1169(99)00109-0

Silyloxy-rhodium(I) complexes of the general formula [{(diene)Rh(μ-OSiMe 3)} 2] ( I) where diene=cod, nbd, showed much higher catalytic activity in the hydrosilylation of 1-hexene by triethoxysilane than respective chloro-rhodium(I) complexes, [{(diene)Rh(μ-Cl)} 2] ( II). Kinetic dependence of the rate on the initial concentration of [Rh] and stoichiometric reactions of Rh-complexes with triethoxysilane and 1-hexene allow a distinction between the catalytic cycles of the reactions occurring in the presence of silyloxy-rhodium vs. chloro-rhodium complexes. Direct reaction of triethoxysilane with ( I) was followed by next elementary steps, in particular reductive elimination of disiloxane (EtO) 3SiOSiMe 3 which generates hydridorhodium(I) complex suggested as an intermediate for the catalysis of the hydrosilylation by silyloxy-rhodium complexes.