Visible light-promoted CO2 fixation with imines to synthesize diaryl α-amino acids

Light-mediated transformations with CO2 have recently attracted great attention, with the focus on CO2 incorporation into C-C double and triple bonds, organohalides and amines. Herein is demonstrated visible light-mediated umpolung imine reactivity capable of engaging CO2 to afford alpha-amino acid derivatives. By employing benzophenone ketimine derivatives, CO2 fixation by hydrocarboxylation of C=N double bonds is achieved. Good to excellent yields of a broad range of alpha, alpha-disubstituted alpha-amino acid derivatives are obtained under mild conditions (rt, atmospheric pressure of CO2, visible light). A procedure that avoids tedious chromatographic purification and uses sustainable sunlight is developed to highlight the simplicity of this method.