Reductive Coupling of CO2 , Primary Amine, and Aldehyde at Room Temperature: A Versatile Approach to Unsymmetrically N,N-Disubstituted Formamides.

We present a simple, metal-free, and versatile route to synthesize unsymmetrically N,N-disubstituted formamides (NNFAs) from CO2 , primary amine, and aldehyde promoted by an ionic liquid (1-butyl-3-methylimidazolium chloride) at room temperature. This approach features wide scopes of amines and aldehydes, and various unsymmetrical NNFAs could be obtained in good to excellent yields. The ionic liquid can be reused for at least five runs without obvious activity loss.