Synthesis and structural characterization of methyl 1 aminoferrocene 1 carboxylate conjugates with alanine

U ovom radu opisana je sinteza i strukturna karakterizacija ferocenskih dipeptida Ac−L−Ala−NH−Fn−CO−OMe (4) i Ac−D−Ala−NH−Fn−CO−OMe (5). Kopulacijom 1'-aminoferocen-1-karboksilata s Boc−L−Ala−OH odnosno Boc−D−Ala−OH dobiveni su prekursori Boc−L−Ala−NH−Fn−CO−OMe (2) i Boc−D−Ala−NH−Fn−CO−OMe (3). Potom je provedena trans- formacija tert-butilkarbamatne skupine u acetamidnu pri čemu su rezultirali ciljni Ac-dipeptidi 4 i 5. Kako bi se provela strukturna i konformacijska karakterizacija, dipeptidi 4 i 5 podvrgnuti su spektros- kopiji nuklearne magnetske rezonancije (NMR) pri čemu su analizirani ₁H-, ₁₃C-, COSY i NOESY NMR spektri. Detektirani NOE kontakti između NHFn i CH₃COOMe pripisuju se intramolekulskoj vodi- kovoj vezi (IHB) NHFnˑˑˑOCCOOMe uslijed koje dolazi do tvorbe 6-članog interlančanog IHB-prstena.This work describes the synthesis and structural characterization of the ferrocene dipeptides Ac−L−Ala−NH−Fn−CO−OMe (4) and Ac−D−Ala−NH−Fn−CO−OMe (5). 1'-Aminoferrocene-1-car-boxylate was coupled with Boc−L−Ala−OH and Boc−D−Ala−OH to give precursors Boc−L−Ala−NH−Fn−CO−OMe (2) and Boc−D−Ala−NH−Fn−CO−OMe (3), respectively. Then, the tert-butylcarbamate groups were transformed into acetamide groups of the enantiomeric dipeptides 4 and 5. For structural and conformational analysis, the goal dipeptides 4 and 5 were subjected to NMR [nu-clear magnetic resonance spectroscopy (₁H-, ₁₃C-, COSY and NOESY)]. The detected NOE contacts between NHFn and CH₃COOMe indicate the presence of intramolecular hydrogen bond (IHB) NHFnˑˑˑOCCO-OMe, i.e., the presence of a 6-membered IHB-ring