Brønsted Acid-Catalyzed C–H Cleavage of Alkenes: Regioselective Access to α-Vinyl, α-Alkynyl Amino Acids

The development of efficient strategies to synthesize α-vinyl and α-alkynyl amino acids is vital for the design and discovery of novel polypeptide drugs. Nevertheless, approaches to α-vinyl and α-alkynyl amino acids are barely provided. Herein, we report a metal-free coupling of alkenes with β,γ-alkynyl-α-ketimino esters. A myriad of unexplored α-vinyl, α-alkynyl amino acid derivatives are furnished via phosphate ester-catalyzed C-H cleavage of alkenes. This reaction demonstrates excellent regioselectivity and an outstanding atom economy. Gram-scale reactions are performed well. The thermally induced single-electron transfer (SET) process in the electron donor-acceptor (EDA) complex sheds light on the transformation.