title: Hydrodefluorination of pentafluoropyridine at rhodium using dihydrogen: detection of unusual rhodium hydrido complexes.
abstract: The pentafluoropyridyl complex [Rh(4-C5NF4)(PEt3)3] (3) reacts with H2 to give initially the dihydrido complex cis-mer-[Rh(H)2(4-C5NF4)(PEt3)3] (6). Within a few hours 2,3,5,6-tetrafluoropyridine as well as two rhodium(III) complexes mer-[Rh(H)3(PEt3)3] (mer-) and fac-[Rh(H)3(PEt3)3] (fac-) are formed. A catalytic C-F activation process for the formation of 2,3,5,6-tetrafluoropyridine starting from pentafluoropyridine and dihydrogen using 3 as a catalyst has been developed. Reaction of [RhH(PEt3)3] (1) with hydrogen affords fac-[Rh(H)3(PEt3)3] (fac-7) and mer-[Rh(H)3(PEt3)3] (mer-7) in a ratio of 1 : 7.25 at 193 K. The latter complex represents the first mononuclear rhodium compound bearing trans-hydrides.
authors: Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Strasse 2, 12489 Berlin, Germany. thomas.braun@chemie.hu-berlin.de
authors: Thomas
authors: T
authors: Braun
authors: Daniel
authors: D
authors: Noveski
authors: Marcel
authors: M
authors: Ahijado
authors: Falk
authors: F
authors: Wehmeier