From simple Ugi adducts to indanes and delta-amidomalonates: new manganese(III)-induced radical cascades.

A complete change of the traditional Ugi adducts framework has been obtained using new radical cascades as Ugi post-condensation reactions. Indanes and delta-amidomalonates were thus obtained in a one-pot procedure from aromatic aldehydes under a sequence involving Ugi addition followed by treatment of the adducts with Mn(III) and malonate or beta-ketoester. The radical step probably involves an intramolecular aryl transfer followed by an oxidative cleavage and final cyclization to indanes.