Aromatic oligoureas: enforced folding and assisted cyclization.
Aromatic oligoureas are forced into well-defined conformation by incorporated intramolecular hydrogen bonds. Shape-persistent tetraureas macrocycles were obtained in a one-step [2+2] reaction in good yields.
Zhang
Aimin
A
Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260, USA.
Han
Yaohua
Y
Yamato
Kazuhiro
K
Zeng
Xiao Cheng
XC
Gong
Bing
B
D001704:Biopolymers / Q000737:chemistry*; D003500:Cyclization; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014508:Urea / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000737:chemistry
D001704:Biopolymers; D014508:Urea