Natural extract-mediated desulfurization towards the sustainable synthesis of isothiocyanates: scope and mechanistic studies

A mild and sustainable protocol for the synthesis of isothiocyanates from anilines has been developed using aqueous banana peel extract as a bio-derived catalytic medium. The transformation proceeds via in situ formation of dithiocarbamate salt intermediates under triethylamine activation, followed by base-induced decomposition using sodium hydroxide. A biphasic ethyl acetate-water system enables efficient conversion under ambient conditions. All the electron donating and electron withdrawing substituted anilines provided their corresponding target products in moderate to good yield. Mechanistic studies clearly confirm that the reaction proceeds with the help of KCl which is present in the WEB. The banana peel extract facilitates interfacial catalysis and enhances reaction efficiency, eliminating the need for toxic reagents, transition-metal catalysts, and harsh conditions. This approach represents a practical valorisation of biomass waste for sustainable organic synthesis.