Double Michael addition of azoles to methyl propiolate: a straightforward entry to ligands with two heterocyclic rings

The synthesis of methyl bis(azol-1-yl)propionates is reported for the first time. These bridge-functionalized bis(azol-1-yl)methanes are prepared by a double Michael addition of azoles to methyl propiolate, representing a new methodology for the synthesis of polydentate ligands.