Starting from the thiacalix[4]arene tetraacetate, novel derivatives bearing four ureido or thioureido functions on the lower rim have been prepared. As proven by NMR titrations, these compounds can bind anions via hydrogen bonding interactions and represent the first example of anion receptors in the thiacalixarene series. (C) 2004 Elsevier Ltd. All rights reserved.
Reactions of Diamines with Isocyanates and Isothiocyanates