Synthesis and conformational analysis of optically active ferrocene containing macrocyclic peptides.
Two macrocyclic peptides 3 and 4 were formed during lactamization of 1,1'-ferrocenylbis(alanine) 1. Isolation, structure determination, and conformational analysis of 3 and 4 are reported as well as a controlled stepwise synthesis of 4 also including an improved route to 1. On the basis of their (1)H NMR spectra recorded at 300 K in DMSO-d(6), the dimer 3 and trimer 4 were found to be C(2) and C(3) symmetric, respectively. As appeared from computational analysis, the low-energy conformations of the macrocyclic peptides were nonsymmetric. Cyclic voltammetry revealed that the ferrocenyl moieties in 3 or 4 are electrochemically equal to ferrocene.
Maricic
Suzana
S
Department of Organic and Bioorganic Chemistry, Lund University, P.O. BOX 124, Sweden.
Frejd
Torbjörn
T
D019281:Dimerization; D005296:Ferrous Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D000075163:Metallocenes; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry*; D013237:Stereoisomerism
D005296:Ferrous Compounds; D000075163:Metallocenes; D010455:Peptides; C004998:ferrocene