Hydroformylation of 2,5-norbornadiene in organic/aqueous two-phase system and acceleration by cationic surfactants

The organic/aqueous biphasic hydroformylation of 2,5-norbornadiene (NBD) was investigated for the first time using HRh(CO)(TPPTS)3 (TPPTS: trisodium salt of tri(m-sulphonylphenyl)phosphine) as the catalyst precursor. A comparison was made of homogeneous and biphasic systems. The optimum reaction parameters are discussed and the reaction mechanism is presented. In order to ensure the process attained high activity under moderate conditions, the effect of various cationic surfactants was tested in the biphasic hydroformylation of NBD. The results indicated that the hydroformylation of NBD in the biphasic system exhibited high activity and high selectivity to dialdehyde products under mild conditions. The addition of cationic surfactants markedly accelerated the reaction. A single long-chain surfactant seemed to exert a greater impact on the hydroformylation of NBD than a double long-chain surfactant. Moreover, the recycling of aqueous solution containing catalyst with or without surfactant was investigated. In the absence of the surfactant, the aqueous catalyst could be recycled six times without a significant decrease in activity and selectivity. Copyright © 2016 John Wiley & Sons, Ltd.