Ruthenium bidentate phosphine complexes for the coordination and catalytic dehydrogenation of amine- and phosphine-boranes

Araminta E W Ledger, Charles E Ellul, Mary F Mahon, Jonathan M J Williams, Michael K Whittlesey

Research output: Contribution to journalArticle

48 Citations (Scopus)

Abstract

Addition of the amine-boranes H3BNH2tBu, H 3BNHMe2 and H3BNH3 to the cationic ruthenium fragment [Ru(xantphos)(PPh3)(OH 2)H][BArF4] (2; xantphos=4,5- bis(diphenylphosphino)-9,9-dimethylxanthene; BArF4=[B{3,5- (CF3)2C6H3}4] -) affords the n1-B-H bound amine-borane complexes [Ru(xantphos)(PPh3)(H3BNH2tBu)H][BAr F4] (5), [Ru(xantphos)(PPh3)(H 3BNHMe2)H][BArF4] (6) and [Ru(xantphos)(PPh3)(H3BNH3)H][BAr F4] (7). The X-ray crystal structures of 5 and 7 have been determined with [BArF4] and [BPh4] anions, respectively. Treatment of 2 with H3BPHPh2 resulted in quite different behaviour, with cleavage of the B-P interaction taking place to generate the structurally characterised bis-secondary phosphine complex [Ru(xantphos)(PHPh2)2H][BPh4] (9). The xantphos complexes 2, 5 and 9 proved to be poor precursors for the catalytic dehydrogenation of H3BNHMe2. While the dppf species (dppf=1,1-bis(diphenylphosphino)ferrocene) [Ru(dppf)(PPh3)HCl] (3) and [Ru(dppf)(n6-C6H5PPh 2)H][BArF4] (4) showed better, but still moderate activity, the agostic-stabilised N-heterocyclic carbene derivative [Ru(dppf)(ICy)HCl] (12; ICy=1,3-dicyclohexylimidazol-2-ylidene) proved to be the most efficient catalyst with a turnover number of 76 h-1 at room temperature.
Original languageEnglish
Pages (from-to)8704-8713
Number of pages10
JournalChemistry - A European Journal
Volume17
Issue number31
DOIs
Publication statusPublished - 25 Jul 2011

Fingerprint Dive into the research topics of 'Ruthenium bidentate phosphine complexes for the coordination and catalytic dehydrogenation of amine- and phosphine-boranes'. Together they form a unique fingerprint.

  • Projects

  • Cite this