A versatile domino process for the synthesis of substituted 3-aminomethylene-chromanones and 2-pyridones catalyzed by CsF

The addition of various primary amines onto 3-α,β-unsaturated diester chromone derivative was studied under mild conditions. Basically, this reaction provided 2-pyridone-based compounds through an interesting domino ‘Addition/Ring Opening/Ring Closure’ process (ARORC). In this study, aniline and tryptamine series exhibited different reactivity profiles leading unexpectedly to 3-aminomethylene chromanones with or without the 2-pyridone derivatives. This constitutes the first description and study of 3-aminomethylene chromanone formation that is supposed to follow a domino process combining ‘Addition/Ring Opening/Ring Closure by Oxa-Michael addition’ (ARORCOM).