One-Pot Synthesis of [1,2,3]Triazolo[1,5-a]quinoxalin-4(5H)-ones by a Metal-Free Sequential Ugi-4CR/Alkyne–Azide Cycloaddition Reaction
A convenient and one-pot approach to prepare [1,2,3]triazolo[1,5-a]quinoxalin-4(5H)-ones by a metal-free sequential Ugi-4CR/alkyne–azide cycloaddition reaction has been developed. The reaction of 2-azidobenzenamines, aldehydes, propiolic acids, and isocyanides produced the Ugi adducts, which were transformed to the [1,2,3]triazolo[1,5-a]quinoxalin-4(5H)-ones in moderate to good yields via alkyne–azide cycloaddition reaction.
Brønsted acid-catalyzed metal-free one-pot synthesis of benzimidazoles via [4+1] heteroannulation of ortho-phenylenediamines with β-oxodithioesters
