Hexakis(PCP-pincer) complexes [C 6{PtBr-(PCP)} 6] (5d) and [C 6{RuCl(PCP)(PPh 3)} 6] (5e) were synthesized via the transcyclometalation (TCM) procedure. Mixing the hexakis(PCHP-arene) ligand 7 with six equivalents of [PtBr(NCN)] (1a) or [RuCl(NCN)(PPh 3)] (1b), respectively, resulted in the selective metalation of all PCP-ligand sites and the concomitant formation of six equivalents of the NCHN-arene ligand. This procedure was found to be superior over existing metalation procedures. In addition, hexakisruthenium complex 5e was applied as homogeneous catalyst in the hydrogen transfer reactions of cyclohexanone, acetophenone and benzophenone to the corresponding alcohols. In these reactions, the activity per ruthenium center of 5e was found to be of the same order of magnitude as that of the mononuclear analogue [RuCl(PCP)(PPh 3)] 3b, indicating that all ruthenium centers act as independent catalytic sites.
Hexakis(PCP-Platinum and –Ruthenium) Complexes by the Transcyclometalation Reaction and their Use in Catalysis / H. P., Dijkstra; M., Albrecht; Medici, Serenella; G. P. M., VAN KLINK; G., VAN KOTEN. - In: ADVANCED SYNTHESIS & CATALYSIS. - ISSN 1615-4150. - 344:10(2002), pp. 1135-1141. [10.1002/1615-4169(200212)344:10<1135::AID-ADSC1135>3.0.CO;2-9]
Hexakis(PCP-Platinum and –Ruthenium) Complexes by the Transcyclometalation Reaction and their Use in Catalysis
MEDICI, Serenella;
2002-01-01
Abstract
Hexakis(PCP-pincer) complexes [C 6{PtBr-(PCP)} 6] (5d) and [C 6{RuCl(PCP)(PPh 3)} 6] (5e) were synthesized via the transcyclometalation (TCM) procedure. Mixing the hexakis(PCHP-arene) ligand 7 with six equivalents of [PtBr(NCN)] (1a) or [RuCl(NCN)(PPh 3)] (1b), respectively, resulted in the selective metalation of all PCP-ligand sites and the concomitant formation of six equivalents of the NCHN-arene ligand. This procedure was found to be superior over existing metalation procedures. In addition, hexakisruthenium complex 5e was applied as homogeneous catalyst in the hydrogen transfer reactions of cyclohexanone, acetophenone and benzophenone to the corresponding alcohols. In these reactions, the activity per ruthenium center of 5e was found to be of the same order of magnitude as that of the mononuclear analogue [RuCl(PCP)(PPh 3)] 3b, indicating that all ruthenium centers act as independent catalytic sites.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
