Photochemically induced electron transfer (PET) catalyzed radical cyclization: a practical method for inducing structural changes in peptides by formation of cyclic amino acid derivatives.

A new radical cyclization reaction of unsaturated amino acid derivatives is presented. The reaction is induced by photoelectron transfer (PET) catalysis and proceeds, in comparison to commonly applied methods, under mild, nonoxidizing, and nontoxic conditions in neutral medium. This type of radical cyclization reaction can be used in peptide chemistry for inducing structural changes in peptides.