Highly Selective Synthesis of 2-Amino-4,6-diarylpyridine Derivatives by the Cascade Reaction of 1,1-Enediamines with α,β-Unsaturated Ketones.

A general and concise method was developed for the synthesis of 2-amino-4,6-diarylpyridine derivatives 4-6 through the cascade reaction, which includes Michael addition, intramolecular cyclization, aromatization, and/or loss of HNO2, of different types of α,β-unsaturated ketones 1 and 1,1-enediamines 2 and 3 in 1,4-dioxane promoted by the base Cs2CO3 or piperidine. This method is suitable for the efficient parallel synthesis of pyridines. A library of highly functional 2-amino-4,6-diarylpyridine derivatives was easily constructed using the cascade reaction described in this study.