Silica Supported Acids (HClO4-SiO2, KHSO4-SiO2) as Eco-friendly Reusable Catalysts for Bromodecarboxylation of α,β-Unsaturated Carboxylic Acids using KBr under Solvothermal and Solvent-Free Conditions

Abstract

A mild procedure has been developed for the bromodecarboxylation of α,β-carboxylic acids using nano silica supported SiO2-HClO4, SiO2-KHSO4 as catalysts and KBr as a bromine source in conventional solvothermal, ultrasonic assisted and solvent-free microwave assisted conditions. The α,β-unsaturated cinnamic acids were converted to corresponding β-bromo styrenes with high regioselectivity, while aliphatic α,β-unsaturated carboxylic acids afforded related β-bromo alkenes.