Synthesis and Characterization of a Novel Hydrido−Alkyl Complex of Rhodium(III) Formed by Intramolecular Activation of a Benzylic C−H Bond: <i>trans</i>-Bis[<i>N</i>-methyl-<i>N</i>-propionyl-2-(diphenylphosphino)benzyl- amine]hydridorhodium(III) Hexafluorophosphate

Abstract

The phosphine N-methyl-N-propionyl-2-(diphenylphosphino)benzylamine (1), reacting with the precursor complex [Rh(NBD)L][PF6] (L = 1, NBD = 2,5-norbornadiene) and molecular hydrogen under ambient conditions, undergoes chelate-assisted C−H bond activation at the benzylic position, quantitatively yielding the five-membered chelate complex trans-[RhH(P(C6H4-o-(CH2N(CH3)COCH2CH3))(C6H5)2)(P(C6H4-o-(CHN(CH3)COCH2CH3))(C6H5)2)][PF6] (4). Extensive spectroscopic studies demonstrate that the rhodium is located in the center of a square bipyramid with an apical hydrogen.