Aqueous-biphasic hydroformylation of 1-hexene catalyzed by the complex HCo(CO)[P(o-C6H4SO3Na)]3

Abstract

The water soluble cobalt complex HCo(CO)[P(o-C₆H₄SO-₃Na)]₃ was used as catalyst precursor for the biphasic aqueous hydroformylation of 1-hexene. The complex was synthesized by reductive carbonylation of CoCl₂.6H₂O in the presence of o-TPPTS ([P(o-C₆H₄SO₃Na)]₃) under nitrogen atmosphere and characterized by FTIR, ¹H NMR and ³¹P {1H} NMR, ¹³C NMR, DEPT – 135, COSY, HSQC, MS (ESI). The catalytic activity of the complex in the biphasic hydroformylation reaction of 1-hexene was evaluated under moderate reaction conditions. The pressure and temperature were varied from 4137 – 7584 kPa (600-1100 psi) of syngas and from 353 – 383 K (80 – 110 °C), respectively. The 1-hexene concentration was varied from 0.021-0,11M and the catalyst from 4x10^-4 - 1.1x10^-3 M. The best conversion at 363 K and 7584 kPa and 7.5 h was 62% with selectivity towards aldehydes (heptanal and 2-methyl-hexanal) of 66% to with l/b ratio of 2.6. The recycling of the catalytic precursor after four successive times, did not show any loss on the activity, having selectivity towards aldehyde up to 60%.