Cobalt‐Catalyzed Reductive Multicomponent Synthesis of β‐Hydroxy‐ and β‐Aminocarbonyl Compounds under Mild Conditions

The cobalt-catalyzed multicomponent reaction between sp2-hybridized organic halides, Michael acceptors and unsaturated electrophiles is described. The reaction proceeds via a formal conjugate addition/aldol or aza-aldol (Mannich) tandem reaction initiated by the in situ metalation of the organic halide by cobalt-catalysis. The essentially new reaction conditions that have been developed are very mild and atom-economic. Under these conditions, a broad range of β-hydroxy- and β-aminocarbonyl compounds are obtained in good to high yields.