One-Pot and Divergent Synthesis of Furo[3,2-c]quinolines and Quinazolin-4(3H)-ones via Sequential Isocyanide-Based Three-Component/Staudinger/aza-Wittig Reaction

Abstract A new one-pot and divergent synthesis of multisubstituted furo[3,2-c]quinolines and quinazolin-4(3H)-ones via sequential isocyanide-based three-component/Staudinger/aza-Wittig reactions was developed. The three-component reactions of dialkyl acetylenedicarboxylates, 2-azidobenzaldehydes (or 2-azidobenzoic acids) and isocyanides gave the azide intermediates, which were subsequently treated with triphenylphosphine to produce polysubstituted furo[3,2-c]quinolines 6 or quinazolin-4(3H)-ones 10 in good overall yields by tandem Staudinger/aza-Wittig reactions.