[PhBP3]RuH(?3-H2SiR2) complexes, which feature electrophilic silicon centers, were found to mediate catalytic reactions of secondary silanes with a variety of polar unsaturated substrates (e.g. ketones, aldehydes, esters, isocyanides). The carbonyl substrates undergo hydrosilation in high yield (> 90 %) to give silyl ethers or silyl acetals. The ?3-H2SiMePh complex mediates a more complex catalytic reaction between XylNC (Xyl = 2,6-dimethylphenyl) and PhMeSiH2 that involves isocyanide hydrosilation and benzylic C-H functionalization to form Si-N and Si-C bonds. The mechanism of this reaction was examined experimentally (low temperature NMR studies, KIE determination) and computationally (DFT), revealing that coordination of the isocyanide to silicon is a key step in the reaction. In contrast, experimental studies of benzophenone hydrosilation indicate that the carbonyl substrate is activated by coordination at ruthenium rather than silicon.

Examining the role of η3-H2SiR2 ligands in catalytic Si-X (X = C, N, O) bond-forming reactions

245th National Meeting (2013)

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