Diastereoselective Deuteration of (Z)-α,β-Dehydrotryptophanyl-Containing Biological Peptides Controlled by Chiral Rhodium Catalysts.

Abstract The regio- and stereoselective labelling ( 2 H, 3 H) of tryptophanyl containing biological peptides catalysed by chiral rhodium complexes is described. The Δ Z Trp-residue is directly produced in the peptide by a catalytic process, involving the ( S )-tryptophan 2′,3′-oxydase from Chromobacterium violaceum . Two biological dehydropentapeptides, pGlu-His-Δ Z Trp-Ser-Tyr and Boc-βAla-Δ Z Trp-Met-Asp-Phe-NH 2 , have been thus synthesized. Asymmetric deuteration of these compounds was then investigated in the presence of various rhodium catalysts. High stereocontrol was achieved by suitable choice of the chiral ligands. This strategy offers new possibilities for the asymmetric synthesis of labelled ( 2 H, 3 H) peptides without ultimate deprotection step.