Photoredox Decarboxylative 3-Fluoroallylation of α-Amino Acids

Abstract

The photocatalytic decarboxylation of α-amino acids is an effective route to α-aminoalkyl radicals which is also amenable to the derivatization of peptides through selective C–C bond formation at the C-terminus. We report that, in the presence of an iridium photocatalyst, allylic difluorides are suitable radical traps to capture α-aminoalkyl radicals produced from α-amino acids, ultimately amounting to a defluorinative 3-fluoroallylation reaction. The catalytic system was applied to the derivatization of a wide breadth of N-protected amino acids and dipeptides in high yields, and the transformation displays great functional group tolerance. α-Amino acids of all substitution levels at the α-carbon led to the desired products in high yields. Post-functionalization of the monofluoroalkene-containing products revealed the potential to attain fluorine-containing organic compounds of greater complexity.