The first direct enantioselective organocatalytic intramolecular Diels-Alder reaction has been accomplished. The use of iminium catalysis has provided a new catalytic strategy for the enantioselective [4+ 2] cycloisomerization of a wide variety of tethered diene-enal systems. The use of imidazolidinones 1 and 2 as the asymmetric catalysts has been found to mediate the enantioselective construction of [4.4. 0] and [4.3. 0] ring systems. Application of this ...
