Visible-Light-Promoted α-Benzylation of N-Phenyl α-Amino Acids to α-Amino Phenylpropanoids.

A new method for the synthesis of α-amino phenylpropanoids under blue light-emitting diode irradiation has been developed through α-C-H benzylation of readily available -phenyl glycine ester with benzyl oxalates as a coupling partner under mild conditions. A range of -phenyl glycine esters were successfully converted to α-amino phenylpropanoid products in moderate to good yields. The utility of this methodology is underlined by its application to the late-state modification of natural products.