Sinteza, spektralna karakterizacija i mehanističke studije novih pirazolskih i pirazolonskih derivata
Author
Marković, Violeta
Mentor
Joksović, MilanCommittee members
Pavlović, VladimirTeodorović, Aleksandar
Marković, Svetlana
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Show full item recordAbstract
U okviru ove doktorske disertacije sintetizovana je serija N-[(1,3-difenil-
pirazol-4-il)metil] α-amino-kiselina i N-[(3-ferocenil-1-fenilpirazol-4-il)-
metil] α-amino-kiselina, uključujući i oba fenilalaninska enantiomera. U NMR
studijama organometalnih derivata zapaženo je da dodatno cepanje orto- i meta-
ferocenskih signala i njihov multiplicitet zavise od prirode α-amino-kiselinskog
bočnog niza i ne mogu se pripisati samo hiralnosti α-amino-kiseline koja je vezana
za pirazolov prsten. Efekat magnetne neekvivalentnosti oba orto-protona
supstituisane ciklopentadienske jedinice naročito je izražen u jedinjenjima sa
aromatičnim ili heteroaromatičnim prstenovima. U serinskom derivatu dobijenom
iz 3-ferocenil-1-fenilpirazol-4-karbaldehida nije primećeno razdvajanje orto-
ciklopentadienskih signala verovatno kao posledica formiranja vodonične veze
između hidroksilne i karboksilne grupe, što ukazuje na postojanje neke druge
konformacije sa umanjenim uticajem hidroksimetil-grupe na ferocens...ki sistem.
Within this doctoral thesis a series of N-[(1,3-diphenylpyrazol-4-yl)methyl] α-amino acids and N-[(3-ferrocenyl-1-phenylpyrazol-4-yl)methyl] α-amino acids including both phenylalanine enantiomer derivatives were synthesized. NMR studies of the organometalic compounds revealed that additional splitting of the ortho and meta ferrocene signals as well as their multiplicities depend on nature of α-amino acid side chain and cannot be attributed to the chirality of pyrazole-linked α-amino acid alone. The effect of magnetic nonequivalence of both ortho protons of substituted cyclopentadiene (Cp) unit is particularly pronounced in compounds containing aromatic or heteroaromatic rings. In serine derivative of 3-ferrocenyl-
1-phenylpyrazole-4-carboxaldehyde there is no appearance of splitting of ortho Cp signals probably as a consequence of hydrogen bond formation between hydroxyl and carboxylate group indicating a presence of an alternate conformation with reduced influence of CH2OH moiety on f...errocene scaffold.