One-pot hydroformylation/hydrogenation of bio-renewable (R)-carvone in a recyclable Rh-catalyzed aqueous biphasic medium: Targeting dual remote sites with a single catalyst

Abstract

A potent methodology was designed for the one-pot hydroformylation/hydrogenation of the biomass-based olefin, (R)-carvone in an aqueous biphasic medium, regiospecifically producing the corresponding linear aldehyde as the desired product. The protocol was made more sustainable as a result of, the reusability of the catalytic system, the use of water as an eco-solvent, the employment of affordable ligand and phase transfer agent. Moreover, only a single Rh-based catalyst was applied for executing distinct reactions at two different remote sites of the substrate. Selectivity tuning of the system with respect to temperature, pressure, concentration of cetyltrimethylammonium bromide (CTAB), catalyst to ligand ratio, kinds of phase transfer agents, aqueous phase volume, reaction time and catalyst to substrate ratio furnished a high chemoselectivity of 97 %, along with a full conversion. The catalytic system could be recycled for at least four consecutive cycles without a significant loss in the activity.