Asymmetric Catalysis with Iron-Salen Complexes

Iron(III)-salen complexes based on a chiral cis-2,5-diaminobicyclo[2.2.2]octane scaffold are used as catalysts for a variety of stereo-selective reactions. High enantio-and diastereoselectivities can be achieved with these catalysts in sulfa-Michael conjugate addition to acyclic alpha,beta,gamma-unsaturated ketones, in regioselective delta-addition of thiols to acyclic alpha,beta,gamma,delta-unsaturated ketones, and in Conia-ene carbocyclization of alkynyl-substituted beta-dicarbonyl compounds. The use of these chiral iron-salen complexes as catalysts provides a new method for conducting these three important reactions under environmentally sustainable conditions.