Examples of Regioselective Anion Recognition among a Family of Two-, Three-, and Four-“Armed” Bis-, Tris-, and Tetrakis(thioureido) [<i>n</i>]Polynorbornane hosts

Abstract

A family of conformationally preorganized, [n]polynorbornane-based anion hosts 1a,b-6a,b have been synthesized. The series includes receptors with 4, 8, and 12 H-bond donors. Using (1)H NMR titration techniques, evaluation of the new hosts against a series of alkyl and aryl dicarboxylates as well as a range of phosphoanionic species has revealed that the tris(thioureido) hosts (in particular 3a) are capable of regioselectively binding dicarboxylates and pyrophosphate (H(2)PPi(2-)).