Reaction of β-(2-aminophenyl)-α,β-Ynones with Tosyl Isocyanate: Experimental and Computational Investigations

A practical metal-free approach to the synthesis of 2-aroyl-N-tosyl-1H-indole-3 carboxamides through an unprecedented sequential 5-endo-dig cycloamination /carboxamidation reaction of β-(2-aminophenyl)-α,β-ynones with the tosyl isocyanate is described. A computational model gives a plausible rationale for the unexpected results