Date: March 11, 2010
Creator: Webb, Joanna R.; Pierpont, Aaron W.; Munro-Leighton, Colleen; Gunnoe, T. Brent; Cundari, Thomas R., 1964- & Boyle, Paul D.
Description: This article discusses the net hydrogenation of Pt-NHPh bond catalyzed by elemental Pt. The addition of H₂ across M-NHR or M-OR moieties is a central reaction for several synthetic transformations. For example, Stryker's reagent, [(Ph₃P)CuH]₆, a catalyst for conjugate addition reactions, is generated by hydrogenolysis of a Cu-OᵗBu bond. Additionally, net H₂ addition across M-O₂CH bonds completes catalytic conversion of CO₂ and H₂ to formic acid, H₂ addition across Pt-OH bonds has been proposed in a cycle for olefin epoxidation, and H₂ addition across M-NHR bonds has been implicated in asymmetric hydrogenations. Despite their importance, reports of well-defined reactions with late(r) transition metal systems are rare and mechanistic studies are limited. Recently, C-H activation of hydrocarbons via net 1,2-addition of C-H bonds across metal-heteroatom bonds using late transition metals (with ≥ 6 d-electrons) bearing formally anionic ligands (e.g., -NHR or -OR) has been reported. Despite interest in these C-H and H-H bond transformations, questions regarding the mechanism remain.
Contributing Partner: UNT College of Arts and Sciences