Dihydroquinazolinones via A3 -Type Reactions of N-Carbamoyliminium Ions.

A variant of the A3 coupling reaction was developed utilizing in situ generated N-carbamoyliminium ions. The tandem INCIC/A3 -coupling sequence provided a facile one-pot synthesis of dihydroquinazolinone derivatives. The scope of the reaction was demonstrated in solution as well as on solid support. The reaction was further combined with peptide synthesis, SN Ar reactions, CuAAC triazole formation or bromination, providing additional opportunities for further diversification of the dihydroquinazolinone scaffolds.