CATALYTIC FORMATION OF OLIGOPEPTIDES FROM ALPHA-AMINO-ACID ESTERS WITH (P-CYMENE)RUTHENIUM(II) COMPLEXES

Consecutive addition of one-equivalent portions of glycine ethyl ester to [(p-cymene)Ru(GGGOMe-H+)Cl] leads to considerable amounts of (tetr a-to nonapeptide)ruthenium complexes in a one-pot reaction, in which t he (p-cymene)RuCl fragment acts as a catalyst. The analogous reaction with alanine methyl ester affords AGGG and AAGGG complexes as the main products. The course of these metal-catalyzed peptide oligomerization s has been followed by mass spectrometry. The synthesis and characteri zation of the pentapeptide complex [(C6Me6)Ru(GGGGGOMe-H+)] is reporte d.