The resurgence of old material: The impact of boehmite-derived catalytic material on the formation of dihydropyran compounds and its application to access fragrant derivatives

Abstract

Bulk materials are the oldest in heterogeneous catalysis, but with the resurgence of recent interest, it has emerged as one of the best catalytic tools to unlock their full potential. Boehmite-derived alumina materials are widely studied for catalytic organic transformations. Despite the progress, understanding the mechanistic insights of its catalytic behaviour has remained obscure. Here, we demonstrate the catalytic performance of a boehmite-derived alumina material to a highly selective catalytic process for the preparation of dihydropyran compounds. The catalytic material displayed excellent activity in terms of conversion (up to 99%) and selectivity (up to 99%). The material was characterized using different techniques and observed that the γ-alumina phase with inherent mild acidic character are key feature for the catalytic activity. Based on NMR and in situ FT-IR spectroscopic investigations a probable mechanism is proposed. This study expands the application of robust material for the preparation of industrially important fragrance compounds. The scope of the catalytic study encompasses a range of substrates and scale-up activities.