A multicomponent synthesis of gem-(β-dicarbonyl)arylmethanes

The reaction of aldehydes with β-dicarbonyls and electron-rich aromatics was investigated to generate in a multicomponent fashion crossed adducts of biological relevance. 4-Hydroxycoumarin, triacetic acid lactone, indole, and a selection of aliphatic and aromatic aldehydes representative of various electronic and steric conditions were employed. The reaction showed a surprising dependence on the solvent, with 1:1 chloroform–water giving the best yield of heterodimeric adducts. The mechanistic rationale for the formation of hetero- rather than homodimeric adducts is discussed.