Synthesis of Pyrrolidines and Pyrrolizidines with α‐Pseudoquaternary Centers by Copper‐Catalyzed Condensation of α‐Diazodicarbonyl Compounds and Aryl γ‐Lactams |
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Authors: | Dr. Sébastien Goudedranche Dr. Céline Besnard Léo Egger Prof. Jérôme Lacour |
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Affiliation: | 1. http://www.unige.ch/sciences/chiorg/lacour/;2. Département de Chimie Organique, Université de Genève, Geneva 4, Switzerland;3. Laboratoire de Cristallographie, Université de Genève, Geneva 4, Switzerland |
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Abstract: | N‐aryl γ‐lactams react intermolecularly with acceptor–acceptor diazo reagents, usually dicarbonyl compounds, in a copper‐catalyzed process to yield functionalized pyrrolidines with α‐pseudoquaternary centers. As 1,2‐acyl or ‐phosphoryl migration is preferred, single regioisomers are obtained. Furthermore, in the presence of a Lewis acid, subsequent Friedel–Crafts reactions yield tricyclic pyrrolizidines in excellent yields (90–96 %) and diastereoselectivities (up to >20:1). |
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Keywords: | acyl migrations diazo reagents γ -lactams pyrrolidines pyrrolizidines |
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