title: Lewis Acid catalyzed dipolar cycloadditions of an activated imidate.
abstract: An evaluation of simple Lewis acids revealed that N-malonylimidates undergo catalyzed [3+2] cycloaddition reactions with aldehydes, imines, and activated olefins to form oxazolines, imidazolines, and pyrrolines, respectively. Reactions proceed optimally at ambient temperature with the addition of 5 mol % of MgCl(2) in CH(3)CN. Experiments aimed at elucidation of the reactive intermediate undergoing cycloaddition suggest that the Lewis acid promotes a 1,2-prototropic shift to give a metal-coordinated azomethine ylide, rather than ionization and proton transfer to give a nitrile ylide.
authors.affiliation: Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, USA.
authors.forename: Roy K
authors.initials: RK
authors.lastname: Bowman
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Johnson