Formic Acid: A Low-Cost, Mild, Ecofriendly, and Highly Efficient Catalyst for the Rapid Synthesis of β-Enaminones

Abstract

β-Enaminones have been synthesized by the condensation reaction of β-diketones with various anilines in the presence of a catalytic amount of formic acid, mild and highly efficient acid catalyst in methanol. These condensation reactions proceed smoothly in short reaction times with near-quantitative yields.

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GRAPHICAL ABSTRACT

Keywords:

• Crystal structure
• β-enaminone
• formic acid
• synthesis

ACKNOWLEDGMENTS

The authors thank the National Science Foundation (CHE-0911061) for financial support. We also acknowledge the Ministerio de Ciencia y Tecnología de Costa Rica (MICIT), Consejo Nacional para Investigaciones Científicas y Tecnológicas (CONICIT), and the Centro de Electroquímica y Energía Química (CELEQ) at the Universidad de Costa Rica for providing partial financial support for an internship for Diego Gonzalez-Flores at Central Michigan University.

Notes

^a Reaction conditions: acetylacetone (1.03 g, 10 mmol), aniline (0.91 g, 10 mmol), acid catalyst (1.0 mol%).

^b Isolated yields.

^a Reaction conditions: acetylacetone (1.03 g, 10 mmol), aniline (0.91 g, 10 mmol), formic acid catalyst (1.0 mol%).

^b Isolated yields.