AMINOBENZANNULATION VIA PHOTOCYCLIZATION REACTIONS OF CHROMIUM DIENYL(AMINO)CARBENE COMPLEXES - SYNTHESIS OF O-AMINO AROMATIC ALCOHOLS

Photolysis of chromium dienyl(amino)carbene complexes is demonstrated to produce o-amino aromatic alcohols. The reaction is proposed to preceed via a chromium-complexed photogenerated dienylketene which undergoes subsequent electrocyclization and aromatization. These reactions are sensitive to the electronic nature of the amino substituent on the carbene carbon and can be tuned by variation in substituents. In particular, the ability to facilitate photolytic ketene generation by employing (acylamino)carbene complexes is illustrated. In addition, new methods of conversion of alkoxycarbene complexes to aminocarbene complexes are described.