LAUSR

Abstract An Ir-mediated photocatalytic coupling of tertiary amines with Ugi-dehydroalanines was developed as an entry to medicinally important 2,4-diaminobutyric acid derivatives. In the process the 2,4-diaminobutyric acid framework is assembled directly embedded into a peptoide structure, via the construction of the C3(sp3)–C4(sp3) bond, through a C H functionalization. The photocatalyzed oxidation of the tertiary amine produce a free radical intermediate which reacts with the double bond present in the dehydroalanines. The complete protocol comprises an Ugi 4-CR followed by an elimination reaction and the photo-induced coupling. Using this strategy, 15 new diversely substituted unnatural α,γ-diamino acids peptide derivatives were prepared in low to good yields.