Metal-Free Michael-Addition-Initiated Three-Component Reaction for the Regioselective Synthesis of Highly Functionalized Pyridines: Scope, Mechanistic Investigations and Applications

A metal-free and completely regioselective three-component synthesis of highly functionalized pyridines from 1,3-dicarbonyl derivatives and Michael acceptors has been achieved. Activated Michael acceptors, that is, ,-unsaturated -oxo carbonyl derivatives, were utilized, allowing substitution at the 4-position and remarkable functional diversity at the 2-position of the pyridine ring. The scope and limitations of this environmentally friendly domino reaction are disclosed, with full experimental data, and the results of mechanistic investigations are discussed.