[Me₂C(C₅H₄)₂TiMe₂]: An Open-Bent Titanocene Catalyst for the Hydro­silylation of Bulky 1,3-Dienes

Abstract

Motivated by our preliminary results on Cp₂TiF₂-catalysed 1,4-hydrosilylation of monosubstituted dienes, we assessed the performance of several titanium complexes for the hydrosilylation of 2,3-dimethylbutadiene, a representative bulky diene. An open-bent titanocene complex [Me₂C(C₅H₄)₂TiMe₂] performed the best and proved to be efficient for the hydrosilylation of a variety of substrates such as disubstituted dienes, activated alkenes, and even an acetylene.

Key words

hydrosilylation - titanium - diene - allylsilane - homo­geneous catalysis

References and Notes

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9

Roullier, L.; Mugnier, Y.; Pousson, E.; Moïse, C.; Richard, P.; Le Gendre, P.; Harvey, P. H. unpublished results.

11

The efficacy of Cp₂TiF₂ in the hydrosilylation of mono-substituted 1,3-dienes prompted us to assess the catalytic performance of the difluoro-ansa-titanocene. Unfortunately, in our hands activation of the ansa-difluorotitanocene precatalyst was not possible.

12

The geometry of 2 was determined to be E by comparison of the NMR spectra with those reported previously, see ref. 5.

13

The E configuration of 5 and 6 was unambiguously determined by NOESY NMR experiments.