A Multicomponent <i>aza</i>‐Prins Strategy for the Diastereoselective Synthesis of Piperidine‐Fused Dihydroquinazolinones

Dihydroquinazolinones (DHQs) and piperidines are widely acknowledged as privileged structures and are of significant interest for the development of new drug candidates. Herein, a novel aza ‐Prins strategy is presented for the synthesis of piperidine‐fused DHQs through a domino multicomponent reaction. Homoallylic ammonium halide salts are found to react with bifunctional aldehydes under acidic conditions to give halide‐substituted fused piperidines in a diastereoselective fashion. The reaction can be extended to the incorporation of alcohol nucleophiles via fine tuning of the reaction conditions. Finally, the utility of the substituted compounds is demonstrated by performing a variety of functionalization reactions on the scaffold.