title: Cobalt-mediated [3 + 2]-annulation reaction of alkenes with alpha,beta-unsaturated ketones and imines.
abstract: The utility of cobalt dinitrosyl complexes for the [3 + 2] annulation of alkenes with unsaturated enones and ketimines has been demonstrated. Reaction of a series of cobalt dinitrosyl/alkene adducts with conjugate acceptors in the presence of Sc(OTf)(3)/LHMDS formed two new C-C bonds at the carbons alpha to the nitrosyl groups of the substrate, leading to unusual tri- and tetracycles. Retrocycloaddition of these products in the presence of norbornadiene yielded functionalized tetrasubstituted bicyclic olefins.
authors.affiliation: Department of Chemistry, University of California, Berkeley, California 94720, USA.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Schomaker
authors.forename: F Dean
authors.initials: FD
authors.lastname: Toste
authors.forename: Robert G
authors.initials: RG
authors.lastname: Bergman
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D003516:Cycloparaffins / Q000737:chemistry*; D007097:Imines / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000475:Alkenes; D003516:Cycloparaffins; D007097:Imines; D007659:Ketones; D009942:Organometallic Compounds; D003035:Cobalt