Cyclic structural motifs in 5,6-dihydroxyindole polymerization uncovered: biomimetic modular buildup of a unique five-membered macrocycle.
An unprecedented 5,6-dihydroxyindole macrocycle (4) featuring a rigid twisted backbone was obtained by biomimetic oxidative cross-coupling of the 2,2'-biindole 2 and triindole 3. A putative reaction intermediate, 2-quinone, was detected and characterized by pulse radiolysis and DFT calculations. Discovery of 4 indirectly supports for the first time theoretically predicted cyclic structural motifs as potential eumelanin building blocks.
Arzillo
Marianna
M
Department of Organic Chemistry and Biochemistry, University of Naples Federico II, Italy.
Pezzella
Alessandro
A
Crescenzi
Orlando
O
Napolitano
Alessandra
A
Land
Edward J
EJ
Barone
Vincenzo
V
d'Ischia
Marco
M
D040761:Biomimetic Materials / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry*; D047028:Macrocyclic Compounds / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D011108:Polymers / Q000737:chemistry*
D007211:Indoles; D047028:Macrocyclic Compounds; D011108:Polymers; C033871:5,6-dihydroxyindole