Silicometallics and catalysis

Abstract

Several processes of silicon substrates (such as hydrosilylation, dehydrogenative silylation and double silylation of alkenes and alkynes, silylative coupling versus cross-metathesis of vinylsilanes with alkenes, polycondensation of divinylsubstituted silicon compounds versus ADMET polymerization, dehydrocoupling of hydrosilanes and silylformylation of acetylene) by transition-metal complexes are briefly overviewed. All the reactions occur via a mechanism involving intermediates containing metal-silicon (i.e. silicometallics versus organometallics) and metal-hydrogen bonds, only occasionally accompanied (sided) by intermediates including metal-carbon bonds.

Controlled and Living Polymerizations Induced with Rhodium Catalysts. A Review

“…Rhodium catalysts have been recently revealed (Takahashi et al 176,177 ) to induce a copolymerization of norbornadiene as well as norborne monomers with CO to give alternating copolymers, i.e., regular polyketones (Fig. 26), in high yields.…”

“…The first of these processes is referred to as silylative coupling polycondensation of divinylsilanes and bis(vinylsilane)s, which, from the formal stoichiometry point of view, proceeds as metathesis, but their mechanism consists of the alternating sequence of Si-C and C-H bond cleavages [165][166][167] (Fig. 24).…”

Synthesis, structure and catalytic activity of the first iridium(I) siloxide versus chloride complexes with 1,3-mesitylimidazolin-2-ylidene ligand

“…The properties of siloxide as an ancillary ligand in the system TM-O-SiR 3 have been effectively utilized in molecular catalysis but predominantly by early transition metal complexes. We have reported previously the synthetic methods and crystal structures of binuclear and phosphine-containing mononuclear rhodium(I) [12] and iridium(I) [13] siloxide complexes, as well as the application of those complexes in catalytic transformations of organosilicon compounds, i.e. silylative coupling of olefins with vinylsilanes [13a,14], curing of polysiloxanes via hydrosilylation [15] as well as hydroformylation [16] and silylcarbonylation [17] of vinylsilanes.…”

Platina-β-diketones as catalysts for hydrosilylation and their reactivity towards hydrosilanes

“…The reactions proved to be highly regioselective, only the anti-Markovnikov product 15 was found (Scheme 4 and Table 4). Additionally, minor amounts (<5 mol%) of ethylbenzene (16) were formed, possibly as the product of a dehydrogenative silylation [24]. Trimethylvinylsilane reacted with methyldiphenylsilane in the presence of platinum complexes as catalysts giving the expected hydrosilylation product 17 (Scheme 4).…”