Synthesis of Quaternary α-Fluorinated α-Amino Acid Derivatives via Coordinating Cu(II) Catalytic α-C(sp3)-H Direct Fluorination.

A coordinating, copper-catalyzed direct α-C(sp3)-H fluorination method has been developed to prepare vital quaternary α-fluorinated α-amino acid derivatives. A Cu(II) catalytic SET oxidative addition mechanism is proposed, involving a key fluoride-coupled Cu(II) charge transfer complex. The protocol can tolerate a rich variety of α-amino acids, for which the auxiliary group is removed in high yield and substituted for the direct preparation of dipeptide derivatives with detachable, single absolute configurations of the target compounds.