Rhodium-catalyzed hydroformylation-cyclization of allylbenzene derivatives

Abstract

Hydroformylation reaction of olefins using CO/H2 mixture (oxo process) is one of the most important metal-catalyzed reactions for the production of aldehydes. In this study, the effects of different reaction parameters (e.g. temperature, CO/H2 pressure, ligand, time) have been studied for the hydroformylation of allylbenzene and eugenol by using rhodium complexes as catalysts. The optimized reaction conditions have been applied successfully in the hydroformylation of different allylbenzene derivatives. Moreover, different 5,6-dihydronaphthalene derivatives have been efficiently synthesized via hydroformylation/cyclization of allylbenzene derivatives by using rhodium catalysts in the presence of catalytic amounts of acid additive. The effect of the type and amount of acid, the type of ligand and the reaction time have been studied thoroughly in order to maximize the chemoselectivity and the yield of the reactions.