Chemistry Letters, Vol.46, No.5, 665-668, 2017
Synthesis and Structural Analysis of Ruthenium-bound Norvaline Peptides
A series of norvaline (Nva) peptides possessing ONO-pincer ruthenium complexes, Boc-{L-[Ru(pydc)(t-Bu-terpy)]Nva}(n)-OMe (n = 2-6), were synthesized successfully by solution-phase peptide synthesis. Efficient coupling of equimolar amounts of N-free Ru-bound norvaline peptides, H-{L-[Ru(pydc)(t-Bu-terpy)]Nva}(n)-OMe, and C-free Ru-bound norvaline, Boc-L-[Ru(pydc)(t-Bu-terpy)]Nva-OH, was achieved by using the 2-chloro-4,6-dimethoxy-1,3,5-triazine-based method. Structural analysis by means of CD and NMR spectroscopy revealed the formation of stable helical conformations in peptides more than three residues.