Toward Enantiomerically Pure β-Seleno-α-amino Acids via Stereoselective Se-Michael Additions to Chiral Dehydroalanines

The first totally chemo- and diastereoselective 1,4-conjugate additions of Se-nucleophiles to a chiral bicyclic dehydroalanine (Dha) are described. The methodology is simple and does not require any catalyst, providing exceptional yields at room temperature, and involves the treatment of the corresponding diselenide compound with NaBH4 in the presence of the Dha. These Se-Michael additions provide an excellent channel for the synthesis of enantiomerically pure selenocysteine (Sec) derivatives, which pose high potential for chemical biology applications.We thank the Agencia Estatal Investigacioń of Spain (AEI; Grants RTI2018-099592-B-C21 and RTI2018-099592-B-C22 projects), the Mizutani Foundation for Glycoscience (Grant 200077), and the EU (Marie-Sklodowska Curie ITN, DIRNANO, Grant Agreement No. 956544). P.O. thanks Universidad de La Rioja for a grant