Theoretical study on copper-catalyzed reaction of hydrosilane, alkyne and carbon dioxide: A hydrocarboxylation or a hydrosilylation process ?

•This work explained why hydrocarboxylation instead of hydrosilylation is preferred.•CO2 insertion process is more favorable kinetically than hydrosilylation process.•Provide helpful information in designing new related reactions.

The hydrocarboxylation and hydrosilylation processes proposed in the copper-catalyzed reaction among carbon dioxide, diphenylacetylene and HSi(OEt)3 were comparatively studied with the aid of density functional theory calculations. Our study is to explore why the reaction preferred a hydrocarboxylation rather than a hydrosilylation process. It was found that the σ bond metathesis between Cu–C and H–Si involved in the hydrosilylation process had a significantly high reaction barrier in the presence of CO2 (47.4 kcal/mol). Instead, CO2 insertion and the subsequent σ bond metathesis between Cu–O and H–Si involved in the hydrocarboxylation process were confirmed kinetically feasible, consistent with the experimental facts.

Graphical abstractThe hydrocarboxylation and hydrosilylation processes proposed in the copper-catalyzed reaction among hydrosilane, alkyne and carbon dioxide were comparatively studied using density functional theory calculations.Figure optionsDownload full-size imageDownload as PowerPoint slide