Bond Activations of PhSiH3 by CP2SmH: A Mechanistic Investigation by the DFT Method

作者：Perrin Lionel; Maron Laurent^*; Eisenstein Odile; Tilley T Don

来源：Organometallics, 2009, 28(13): 3767-3775.

DOI：10.1021/om900106n

In this paper, a theoretical investigation of bond activations of PhSiH3, catalyzed by CP2SmH, is proposed by examination of the energy profiles of these reactions. The formation of the minor and major products observed experimentally is rationalized. The experimentally proposed two-step mechanism, starting with a Si-C activation to give CP2SmPh as an intermediate, is confirmed. The second step involves reaction of this intermediate with the Si-H bond of Ph2SiH2 to give Ph2SiH2 and regenerate the samarium hydride. The relative free enthalpy barriers of these two steps are in agreement with the lack of observation of any intermediate during the catalytic reaction. In addition to the main experimentally proposed mechanism, a second mechanism that involves two successive Si-H activations is proposed in order to account for the formation of byproducts. Theoretically, these two reactions are demonstrated to occur competitively, which explains the formation of secondary products arising from redistribution and dehydrocoupling.

• 出版日期2009-7-13
• 单位中国地震局