Role of Solvent in Fine-Tuning the Selectivity in Geraniol Transformation Using 20% FeCl3/MCM-41

Abstract

A nature-inspired selective synthesis of the Linalool and the role of the solvent in the selectivities of the products Linalool, Digeranyl Ether (DGE) and Geranyl Linalyl Ether (GLE) is reported in this research work using the 20% FeCl3/MCM-41 supported solid acid catalyst. The textural and microscopic properties of the catalyst were revealed using SAXRD, WAXRD, PyIR, TEM and XPS studies contributing to the acidity and stability of the catalyst which was further exploited for transformation of Geraniol into rearranged and etherification products. 100% selectivity of the Linalool was achieved in only Pet Ether owing to the Brønsted acidity of the catalyst which was further established by the catalyst masking studies with 2,6-lutidine. The Lewis as well as Brønsted acidity of the catalyst in polar aprotic DCM solvent accounts for product distribution to give 76% conversion and Linalool (37%), DGE (35%) GLE (18%) selectivities. The meticulous and detailed optimization studies contributed in condensing the accurate quantification of the reaction conditions and suggesting role of Lewis and Bronsted acidity of Catalyst in deciphering the plausible mechanism. The sustainability of the 20% FeCl3/MCM-41 catalyst was well established by confirming the speciation of Fe(III) by XPS after the recycle studies.