Volume 128, Issue 37 pp. 11319-11323
Zuschrift

Medium-Ring Nitrogen Heterocycles through Migratory Ring Expansion of Metalated Ureas

Jessica E. Hall

Jessica E. Hall

School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS UK

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Dr. Johnathan V. Matlock

Dr. Johnathan V. Matlock

School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS UK

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Dr. John W. Ward

Dr. John W. Ward

School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS UK

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Katharine V. Gray

Katharine V. Gray

School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL UK

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Prof. Jonathan Clayden

Corresponding Author

Prof. Jonathan Clayden

School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS UK

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First published: 21 July 2016
Citations: 50

Abstract

Simple benzo-fused nitrogen heterocycles (indolines, tetrahydroquinolines, and their homologues) undergo migratory ring expansion through deprotonation of their benzylic urea derivatives with lithium diisopropylamide (LDA) in the presence of N,N′-dimethylpropylideneurea (DMPU). The products of the reactions are benzodiazepines, benzodiazocines, and their homologues, with ring sizes of 8–12. The reactions tolerate a range of substituent patterns and types, and may exhibit enantiospecificity or diastereoselectivity. Considerable complexity is rapidly generated in an efficient synthesis of these otherwise difficult-to-obtain medium-ring nitrogen heterocycles.

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