NEUARTIGE BASISCHE LIGANDEN FUER DIE HOMOLOGENKATALYTISCHE METHANOLCARBONYLIERUNG V. KOMPLEXCHEMISCHES VERHALTEN MEHRZAENIGER FURFURYLPHOSPHANE UND IHR EINFLUSS AUF DIE SELEKTIVITAET UND DEN UMSATZ BEI DER ETHANOLSYNTHESE AUS METHANOL

Article abstract of DOI:10.1016/S0022-328X(00)99730-4

The potentially four-, three- and bidentate furfurylphosphanes RP(CH2C4H3O)2 (3a-e) (R = Ph (a), Mes (b), Me (c), t-Bu (d), CH2C4H3O (e), Et (f) and Ph2PCH2C4H3O (5) react with (OC)5WTHF to give pentacarbonyltungsten complexes (OC)5WPR(CH2C4H3O)2 (4a-e) and (OC)5WPPh2CH2C4H3O (6), respectively.Irradiation of ether solutions of 4a-e and 6 leads to the formation of the tetracarbonyltungsten complexes (OC)4WPR(CH2C4H3O)2 (8a-e) and (OC)4WPPh2CH2C4H3O (9), respectively.In a similar way (OC)4WPPh2C2H4(CH3)H2O (10) is obtained from Ph2PC2H4C4(CH3)H2O (1) and (OC)5WTHF via the intermediate compound (OC)5WPPh2C2H4(CH3)H2O (7).Furyl-oxygen-metal interactions do not occur.Only one furyl ring is η²-bonded to the metal in 8a-e, 9 and 10.As was exemplified by 8e and 9 this very weak bond is easily cleaved by phosphanes.The influence of the furylphosphanes 1, 3a-f and their phosphonium salts Br (13a,d,e), I (13f) and Br (14) and the furylphosphanes RP(C4H3O)2 (15a,c,d) and Ph2PC4H3O (16) on the homologation of methanol to ethanol was investigated using cobalt as catalyst metal and iodine as a promotor.In accordance with their complex chemical behaviour the best results with respect to selectivity and conversion were obtained with the bidentate ligands 5 and 16.