Template-directed synthesis of cucurbituril analogues using propanediurea as a building block†
Abstract
Two novel cucurbituril-like macrocycles, TD[4] and TD[5], were prepared from the condensation of propanediurea and formaldehyde using CaCl2 and BaCl2 as templates, respectively, featuring convenience and low cost. The two hosts show excellent thermostability and their structures were characterized by 1H NMR, HRMS and single crystal X-ray diffraction.