Synthesis and structural characterization of [(C5H4)SiMe2(N-t-Bu)]Ti[(o-C6H4)C(Ph)C(Ph)], generated via an alkyne-Ti benzyne coupling reaction

The thermolysis of [(C5H4)SiMe2(N-t-Bu)]TiPh2 in the presence of diphenylacetylene proceeds at 80 °C in cyclohexane solution with the sole formation of the titanacyclic complex [(C5H4)SiMe2(N-t-Bu)]Ti[(o-C6H4)C(Ph)C(Ph)], which has been characterized by solution NMR measurements and X-ray crystallographic analysis. This reaction is accompanied by the elimination of benzene and presumably occurs via coupling of a titanium benzyne intermediate with diphenylacetylene. The two chemically inequivalent Ti–C bonds of 2.081(7) and 2.103(6) Å in [(C5H4)SiMe2(N-t-Bu)]Ti[(o-C6H4)C(Ph)C(Ph)] reflect the increased electrophilicity of the d0 Ti(IV) center arising from the presence of the bifunctional ansa-cyclopentadienyldimethylsilylamido ligand.

Graphical abstractThe thermolysis of [(C5H4)SiMe2(N-t-Bu)]TiPh2 in the presence of diphenylacetylene proceeds at 80 °C in cyclohexane solution with the formation of the titanacyclic complex [(C5H4)SiMe2(N-t-Bu)]Ti[(o-C6H4)C(Ph)C(Ph)], which has been characterized by NMR and X-ray crystallography.Figure optionsDownload full-size imageDownload as PowerPoint slide