Late-Stage C-H Functionalization of Dehydroalanine-Containing Peptides with Arylthianthrenium Salts and Its Application in Synthesis of Tentoxin Analogue

Dehydrophenylalanine has a characteristic unsaturated double bond that makes it indispensable in the context of peptides and proteins. In this study, we report the Pd-catalyzed C(sp²)-H arylation of dehydroalanine-containing peptides with arylthianthrenium salts under mild and base free conditions, which provides efficient access to dehydrophenylalanine-containing peptides. This approach enables the efficient coupling of different drug scaffolds and bioactive molecules to the peptides. Remarkably, the method could be used for the concise synthesis of tentoxin and its analogue.