Schomaker, Jennifer M. Toste, F. Dean Bergman, Robert G. Cobalt-Mediated [3 + 2]-Annulation Reaction of Alkenes with α,β-Unsaturated Ketones and Imines 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)<sub>3</sub>/LHMDS formed two new C−C bonds at the carbons α 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. adduct;functionalized tetrasubstituted bicyclic olefins;norbornadiene;series;Annulation;Imine;presence;Retrocycloaddition;ketimine;tetracycle;utility;Alkene;annulation;alkene;carbons α;Ketone;nitrosyl groups;Sc;enone;conjugate acceptors;substrate;cobalt dinitrosyl complexes;tri;Unsaturated;bond 2009-08-20
    https://acs.figshare.com/articles/journal_contribution/Cobalt_Mediated_3_2_Annulation_Reaction_of_Alkenes_with_Unsaturated_Ketones_and_Imines/2834410
10.1021/ol901542n.s002