Synthesis of ß‐Substituted Dehydroamino Acids via Formal C–H Functionalization of Dehydroalanine with Diazo Precursors

Recent advances in peptide drug discovery inspired the discovery of novel synthetic methods to access diverse noncanonical amino acids (ncAAs). Dehydroamino acids (ΔAAs) provide opportunities for not only the generation of ncAA building blocks but also late‐stage functionalizations of the α,ß‐desaturation via diverse transformations. Herein, we report a general synthetic method accessing ß‐substituted ΔAAs via formal C–H functionalization of dehydroalanine derivatives. The mild reaction conditions allow broad functional group compatibility and the products provide entries into the novel chemical space of ncAAs.