Dimanganese decacarbonyl catalyst has been evaluated in the reactions of HSiR3 (R = Et, OEt) with R'OH (R' = Me, Et, i-Pr, t-Bu and benzyl), under various conditions. The order of reactivity of the alcohols decreases when more bulky alkyl groups are used, and that of the silanes increases if a more electron-withdrawing group (OEt) is used. Kinetic analysis indicates that the reaction is first order with respect to the silane, to the alcohol and to the catalyst. The effects of varying the solvent and adding a phosphine ligand have also been investigated.
Dimanganese decacarbonyl catalyst has been evaluated in the reactions of HSiR3 (R = Et, OEt) with R'OH (R' = Me, Et, i-Pr, t-Bu and benzyl), under various conditions. The order of reactivity of the alcohols decreases when more bulky alkyl groups are used, and that of the silanes increases if a more electron-withdrawing group (OEt) is used. Kinetic analysis indicates that the reaction is first order with respect to the silane, to the alcohol and to the catalyst. The effects of varying the solvent and adding a phosphine ligand have also been investigated.
Silica-supported iridium catalysts have been evaluated in the reactions of HSiR3 (R Et, OEt) and Me3SiO[Si(H)(Me)O]nSiMe3 (PS1, n 1; PS50, n ∼ 50) with awide variety of primary alcohols. Catalysts obtained by reaction of IrCl(CO)[Ph2P(CH2)2Si(OEt)3]2 with silica are rapidly deactivated in a manner similar to the related homogeneous systems. More active catalysts are obtinaed by treating the silica first with Ph2P(CH2)2Si(OEt)3 and then with [IrCl(C8H14)2]2. The order reactivity of the silanes is PS50 ⪢ HSi(OEt)3 > HSiEt3 ⪢ PS1, and that of the alcohols reflects principally the bulk of the organic group. Kinetic analysis indicates two pathways involving iridium bound to the phosphine and directly to the silica. The 29 Si{1H} NMR spectra of PS50 and the product of its reaction with Ph(CH2)2OH are reported.