Abstract The synthesis of a new class of potential anion hosts, the 2-(guanidiniocarbonyl) furans 5a–d, is presented in this study. The facile decomposition of furans under acidic conditions makes the synthesis of these compounds challenging. First binding studies showed that the (guanidiniocarbonyl) furans are much more acidic (pK a≈ 5.5) than the analogous pyrroles (pK a≈ 7) previously introduced by us for oxoanion binding in ...
