Volume 25, Issue 30 p. 7270-7274
Communication

Highly Enantio- and Diastereoselective Catalytic Asymmetric Tamura Cycloaddition Reactions

Aarón Gutiérrez Collar

Aarón Gutiérrez Collar

School of Chemistry Trinity Biomedical Sciences Institute, Trinity College Dublin, 152-160 Pearse Street, Dublin, 2 Ireland

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Dr. Cristina Trujillo

Dr. Cristina Trujillo

School of Chemistry Trinity Biomedical Sciences Institute, Trinity College Dublin, 152-160 Pearse Street, Dublin, 2 Ireland

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Prof. Stephen J. Connon

Corresponding Author

Prof. Stephen J. Connon

School of Chemistry Trinity Biomedical Sciences Institute, Trinity College Dublin, 152-160 Pearse Street, Dublin, 2 Ireland

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First published: 02 May 2019
Citations: 11

Graphical Abstract

Tetralone and easy target: A highly enantio- and diastereoselective Tamura cycloaddition process involving simple α,β-unsaturated imines to yield malleable α-tetralones is reported. In addition, DFT calculations provided insight into the catalyst mode of action and the origins of the observed enantiocontrol.

Abstract

The first broad-scope catalytic asymmetric Tamura cycloaddition reactions are reported. Under the influence of anion-binding bifunctional catalysis a wide range of α,β-unsaturated N-trityl imines undergo reactions with enolisable anhydrides to form highly synthetically useful α-tetralone structures with excellent enantio- and -diastereocontrol. In stark contrast to the previous literature benchmarks, doubly activated or highly electron deficient alkenes are not required. A facile two-step, high yielding sequence can convert the cycloadducts to α-haloketones (challenging to generate catalytically by other means) with the net formation of two new C−C bonds and three new contiguous stereocentres with exquisite stereocontrol. A DFT study has provided insight into the catalyst mode of action and the origins of the observed enantiocontrol.