Oxygen‐Promoted CH Bond Activation at Palladium. (9th May 2014)

• Record Type: Journal Article
• Authors: Scheuermann, Margaret L.; Boyce, David W.; Grice, Kyle A.; Kaminsky, Werner; Stoll, Stefan; Tolman, William B.; Swang, Ole; Goldberg, Karen I.
• Is Part Of: Angewandte Chemie. Volume 126:Number 25(2014)
• Page Start: 6610
• Page End: 6613
• Publication Date: 2014-05-09
• Subjects: C‐H‐Aktivierung -- Hydroxylierungen -- Palladium -- Peroxo -- Superoxo; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201402484
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: [Pd(P(Ar)( t Bu)2 )2 ] (1, Ar=naphthyl) reacts with molecular oxygen to form Pd II hydroxide dimers in which the naphthyl ring is cyclometalated and one equivalent of phosphine per palladium atom is released. This reaction involves the cleavage of both CH and OO bonds, two transformations central to catalytic aerobic oxidizations of hydrocarbons. Observations at low temperature suggest the initial formation of a superoxo complex, which then generates a peroxo complex prior to the CH activation step. A transition state for energetically viable CH activation across a Pdperoxo bond was located computationally. Abstract : Peroxo greift an: [Pd(P(Ar)( t Bu)2 )2 ] (Ar=Naphthyl) reagiert mit molekularem Sauerstoff unter C‐H‐ und O‐O‐Bindungsspaltung. Bei tiefen Temperaturen wird die anfängliche Bildung eines Superoxo‐Komplexes beobachtet, der vor dem C‐H‐Aktivierungsschritt in einen Peroxo‐Komplex übergeht. Eine energetisch plausible C‐H‐Aktivierung durch die Pd‐Peroxo‐Bindung wurde rechnerisch identifiziert.