Angewandte Chemie · 2015 · 13 citations · 35 references
Natural SciencesChemistryOrganic ChemistryOrganometallic ChemistrySynthetic Medicinal ChemistryAddition ReactionsHeterocycle SynthesisHeterocyclic ChemistryOrganic SynthesisAlkyne Cycloaddition ReactionsCycloaddition ReactionsHeterocycle FunctionalizationIntramolecular Electron TransferProton Transfer ReactionsPyrrolidine SynthesisSchiff Base CatalysisStereoselectivity
Abstract A new “single‐flask” method was developed for the synthesis of imidazolidines and pyrrolidines with high stereoselectivity. First, a Schiff base was arylated with an aryne. Second, an intramolecular proton transfer took place from the methylene position to the anionic aryne ring. Third, the resultant ylide reacted with a second equivalent of the same Schiff base in situ or an electron‐deficient alkene through a (3+2) cycloaddition. These sequential tandem 1,2‐addition/(3+2) cycloaddition reactions led to the desired heterocycles in 63–88 % yields.
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