The ‘Azirine/Oxazolone Method’ on Solid Phase: Introduction of Variousα,α-Disubstitutedα-Amino Acids

Abstract

Peptides containing various α,α-disubstituted α-amino acids, such as α-aminoisobutyric acid (Aib), 1-aminocyclopentane-1-carboxylic acid, α-methylphenylalanine, and 3-amino-3,4,5,6-tetrahydro-2H-pyran-3-carboxylic acid have been synthesized from the N- to the C-terminus by the ‘azirine/oxazolone method’ under solid-phase conditions. In this convenient method for the synthesis of sterically demanding peptides on solid-phase, 2H-azirin-3-amines are used to introduce the α,α-disubstituted α-amino acids without the need for additional reagents. Furthermore, the synthesis of poly(Aib) sequences has been explored.