1-octyne, hydrosilylation

NHC Plotinum(O) Complexes Unique Catalysts for the Hydrosilylation ofAlkenes and Alkynes Table 5.5 Catalyst screening for the hydrosilylation of 1-octyne. 

The electronic and steric nature of silane is usually decisive in controlling the selectivity of catalytic hydrosilylations. Therefore, the hydrosilylation of 1-octyne (31), in the presence of various silanes and under the usual conditions was studied (Table 5.6) [32]. Due to its previous success, (IPr)Pt(dvtms) 15g was selected to catalyze this reaction. However, since the effect of the silane should be assessed without interference from the NHC sterics, we performed the reactions with PtCl2(cod), a platinum(O) species devoid of a bulky ligand, as control experiments. Whereas the influence of the electronic properties of the silane is... 

This second-generation catalyst rapidly showed its value and, after a small optimization of the reaction conditions, outstanding results were obtained in the hydrosilylation of 1-octyne (31) with bis(trimethylsilyloxy)methylsilane (3) (Scheme 5.13) [35]. The outcome of the reaction revealed it to be rather sensitive to catalyst loading and a significant decrease in selectivity was observed when... 

Scheme 5.13 Optimized conditions for the hydrosilylation of 1-octyne (31) by MCiM (3) using second-generation catalyst 45.

Marko and co-workers extended their hydrosilylation reactions of alkenes to terminal alkynes. Initially, complexes 80-type were screened in the hydrosilylation of 1-octyne by bis(tiimethylsilyloxy)methylsilane as model reaction and enhanced selectivity was observed when bulky aryl substituted NHCs were employed (IPr and SlPr). ... 

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