Hydrogen-Bonded Complexes of Diaminopyridines and Diaminotriazines: Opposite Effect of Acylation on Complex Stabilities
作者:Felix H. Beijer、Rint P. Sijbesma、Jef A. J. M. Vekemans、E. W. Meijer、Huub Kooijman、Anthony L. Spek
DOI:10.1021/jo960612v
日期:1996.1.1
from 890 to ca. 6 M(-)(1). This phenomenon is related to different conformational preferences of these compounds. The amide groups in bis(acylamino)pyridines prefer a trans conformation, with the carbonyl group anti with respect to the ring nitrogen and coplanar with the aromatic ring. The amides of bis(acylamino)triazines, however, reside predominantly in a cisconformation. Repulsive secondary electrostatic