High pressure infrared and nuclear magnetic resonance studies of the rhodium-sulfoxantphos catalysed hydroformylation of 1-octene in ionicliquids

摘要

The rhodium-sulfoxantphos catalysed hydroformylation of 1-octene in 1-n-butyl-3-methylimidazolium hexafluorophosphate(BMI.PF_6)as a room temperature ionic liquid was monitored in situ by high pressure IR(HP-IR)and NMR(HP-NMR).Similar ee(bis-equatorial)and ea(equatorial-apical)(diphosphine)Rh(CO)_2H catalytic species,as observed in organic solvents,are formed in the BMI.PF_6 ionicliuid.The ratio of the ee and ea isomers is influenced by both the temperature and syngas pressure.An increase in hydrogen partial pressure has no effect on the activity of the system during the reaction performed in BMI:PF_6,while some hydrogormylation systems using xanthene backbone ligands in conventional organic solvents can be sensitive to hydrogen partial pressure.