A one-pot synthesis of [1,2,3]triazolo[1,5-a]quinoxalines from 1-azido-2-isocyanoarenes with high bond-forming efficiency

An efficient approach to prepare 1,2,3-triazolo[1,5-a]quinoxaline scaffolds, starting from 1-azido-2-isocyanoarenes and terminal acetylenes or substituted acetaldehydes, has been developed. In the case of trifluoromethylation triggered cyclization, four chemical bonds, including two C-C and two C-N bonds, were formed consecutively without isolating the triazole intermediate. In addition, these triazo-fused products were readily transformed into diversified quinoxaline derivatives via rhodium-catalyzed carbenoid insertion reactions.