Intermolecular Photocatalytic C–H Functionalization of Electron-Rich Heterocycles with Tertiary Alkyl Halides

Elizabeth C. Swift; Theresa M. Williams; Corey R. J. Stephenson

doi:10.1055/s-0035-1561320

Synlett, Table of Contents

Synlett 2016; 27(05): 754-758
DOI: 10.1055/s-0035-1561320

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Intermolecular Photocatalytic C–H Functionalization of Electron-Rich Heterocycles with Tertiary Alkyl Halides

Elizabeth C. Swift

Department of Chemistry, University of Michigan, 930 N. University Ave, Ann Arbor, MI 48109, USA Email: crjsteph@umich.edu

,

Theresa M. Williams

Department of Chemistry, University of Michigan, 930 N. University Ave, Ann Arbor, MI 48109, USA Email: crjsteph@umich.edu

,

Corey R. J. Stephenson*

Department of Chemistry, University of Michigan, 930 N. University Ave, Ann Arbor, MI 48109, USA Email: crjsteph@umich.edu

› Author Affiliations

Abstract

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Abstract

The coupling of tertiary alkyl halides with electron-rich arenes is promoted by visible-light photoredox catalysis. Tris[2-phenylpyridinato-C ²,N]iridium(III) [Ir(ppy)₃] was the optimal catalyst, enabling direct reduction of the halide from the excited state, and thereby eliminating the requirement for a stoichiometric electron donor. High yields were obtained when the aromatic component was used in excess, although equimolar amounts afforded only slightly diminished yields. The reaction tolerates a number of functional groups, including allyl, ester, amide, or carbamate. The efficiency of this reaction has been improved through demonstration of scale-up in flow, and a new substituted Ir(ppy)₃ derivative was isolated and characterized.

Key words

photoredox - catalysis - alkylation - C–H functionalization - quaternary carbon - flow reaction

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References

References and Notes

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Supporting Information