Sulfones multidentate

Poyatos et al. investigated the activity of the N-C-chelating oxazole-NHC containing Pt complex 142 with various substrates (Figure 13.16). From phenylacetylene, the p-( )-isomer and the a-isomer were the only two reaction products (60 40 respectively). Styrene hydrosilylation led to the formation of the linear product with 85% selectivity (70% conv.). The cationic Pt" complex, 143, of multidentate NHC, was found to be an efficient catalyst precursor for hydrosilylation of alkynes, and only a- and p-( ) regioisomers were produced (Figure 13.16). The water-soluble Pt complex 144, bearing sulfonated NHC, was an active and recyclable catalyst for the hydrosilylation of phenylacetylene and other alkynes at room temperature in water. ... 

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