Modification of rhodium catalyst with stibines for hydroformylation of 1-pentene

Abstract

Homogeneous hydroformylation of I -pentene under synthesis gas experimental conditions was studied using RhClCO(PPh3)2 complex with different triarylstibines. Three different stibine ligands SbR3 [where R = 2,4,6-mesityl (TMS), 2-furyl (TFS), 2-N,N-dimethylbenzylamine (TDMBAS)], have been tested. It is interesting to note that 2: 1 addition of these stibine ligands to the RhCICO(PPh3)2 complex catalyst increases the aldehydes yields with an appreciable n:iso ratio. The catalytic activity of the system shows a TDMBAS > TMS > TFS pattern which indicates that not only basicity of the ligand alone is playing a role in the activity but the steric effect is also very important, and it is combination of these two factors that contributes to the resulting catalytical activity. The maximum yield of aldehydes obtained were 98.7% with n/iso = 1.4 when RhCICO(PPh3)2 + TFS system was used and 93.7% with n/iso = 2.43 when TDMBAS ligand was studied.