Hydrosilylation of aromatic nitriles promoted by solvated rhodium atom-derived catalysts

Rhodium metal particles, isolated as supported or unsupported powder starti ng from mesitylene solvated rhodium atoms, catalyse the hydrosilylation of aromatic nitriles to N,N-disilylamines in high conversion at 100 degrees C. Different hydrosilanes (HSiMe3, HSi(OEt)(3)) can be employed. In the case of cinnamonitrile, the chemoselectivity of the reaction to 2-trimethylsilyl -3-phenylpropionitrile and (E)- and (Z)-1-di(trimethylsilyl)amino-3-phenyl- 1-propene is strongly dependent on the reaction temperature. The commercial rhodium on gamma-Al2O3 catalyst is considerably less active and selective than the analogous catalyst prepared via Metal Vapour Synthesis (MVS) proba bly owing to the different dimension and distribution of the metal particle s in the two samples as shown by HRTEM analysis. (C) 1999 Elsevier Science B.V. All rights reserved.