282087-73-4Relevant academic research and scientific papers
Rhodium complexes based on phosphorus diamide ligands: catalyst structure versus activity and selectivity in the hydroformylation of alkenes
Van Der Slot, Saskia C.
, p. 2504 - 2515 (2008/10/08)
The rhodium-catalyzed hydroformylation reaction of 1-octene with phosphorus diamide ligands has been investigated. Four monodentate phosphorus diamide ligands and six bidentate phosphorus diamide ligands derived from a 1,3,5-trisubstituted biuret structure have been synthesized. These types of ligands combine steric bulk with π-acidity. The rhodium complexes formed under CO/H2 have been characterized by high-pressure spectroscopic techniques. Spectroscopic experiments revealed that the monodentate ligands form mixtures of HRhL2(CO)2 and HRhL(CO)3. The ratio HRhL2(CO)2:HRhL(CO)3 depends on the ligand concentration and its bulkiness. The bidentate ligands form stable, well-defined catalysts with a specified structure under hydroformylation conditions. Both monodentate and bidentate ligands have been tested in the hydroformylation reaction of 1-octene. The monodentate ligands form very active catalysts, but the linear-to-branched ratio of the product is low. The bidentate ligands show improved selectivity compared to the monodentate ligands and an activity that is only slightly lower.
