Stabilized Carbon‐Centered Radical‐Mediated Carbosulfenylation of Styrenes: Modular Synthesis of Sulfur‐Containing Glycine and Peptide Derivatives

Abstract

Abstract Sulfur‐containing amino acids and peptides play critical roles in organisms. Thiol‐ene reactions between the thiol residues of L‐cysteine and the alkenyl fragments in the designed coupling partners serve as primary tools for constructing C─S bonds in the synthesis of unnatural sulfur‐containing amino acid derivatives. These reactions are favored due to the preference for hydrogen transfer from thiol to β‐sulfanyl carbon radical intermediates. In this paper, the study proposes utilizing carbon‐centered radicals stabilized by the capto‐dative effect, generated under photocatalytic conditions from N–aryl glycine derivatives. The aim is to compete with the thiol hydrogen, enabling radical C─C bond formation with β‐sulfanyl carbon radicals. This protocol is robust in the presence of air and water, offers significant potential as a modular and efficient platform for synthesizing sulfur‐containing amino acids and modifying peptides, particularly with abundant disulfides and styrenes.

Keywords

• capto‐dative effect
• carbosulfenylation
• photocatalysis
• radicals
• sulfur‐containing amino acids