A novel dicationic phenoxaphosphino-modified Xantphos-type ligand: a ligand for highly active and selective, biphasic, rhodium catalysed hydroformylation in ionic liquids

Dalton Transactions Pub Date: 2004-04-16 DOI: 10.1039/B403261F

Abstract

A highly active and regioselective catalyst obtained from a novel dicationic ligand (1) and Rh(CO)2(acac) for hydroformylation of 1-hexene and 1-octene in ionic liquids is reported. Optimisation studies of various reaction parameters led to an unprecedentedly active (TOFs > 6200 mol mol?1 h?1, T = 100 °C), selective (l/b ratios > 40) and stable hydroformylation procedure. No catalyst leaching (Rh-loss < 0.07% of initial rhodium intake, P-loss < 0.4% of the initial phosphorus intake) or losses in performance could be measured during 1-octene hydroformylation recycle experiments in 1-butyl-3-methylimidazolium hexafluorophosphate. At low catalyst loadings activities and regioselectivities competitive with one-phase catalysis in conventional solvents were observed. At high catalyst loadings the system is extremely stable and has a long shelf-life as a result of the formation of stable, if inactive rhodium dimers.

catalysis: homogeneous
Graphical abstract: A novel dicationic phenoxaphosphino-modified Xantphos-type ligand: a ligand for highly active and selective, biphasic, rhodium catalysed hydroformylation in ionic liquids
Recommended Literature