Visible-light-mediated conversion of alcohols to halides

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The development of new means of activating molecules and bonds for chemical reactions is a fundamental objective for chemists. In this regard, visible-light photoredox catalysis has emerged as a powerful technique for chemoselective activation of chemical bonds under mild reaction conditions. Here, we report a visible-light-mediated photocatalytic alcohol activation, which we use to convert alcohols to the corresponding bromides and iodides in good yields, with exceptional functional group tolerance. In this fundamentally useful reaction, the design and operation of the process is simple, the reaction is highly efficient, and the formation of stoichiometric waste products is minimized.

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Figure 1: Phosphine-free halogenation of alcohols using visible-light photoredox catalysis.
Figure 2: Ru(bpy)3Cl2 catalysed bromination of alcohol 1a.
Figure 3: Mechanistic investigation of the photocatalytic halogenation.
Figure 4: Degenerate SN2 reaction results in racemization with optically enriched alcohol 11.


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This work was supported by the donors of the American Chemical Society Petroleum Research Fund (48479-G1) and Boston University. Nuclear magnetic resonance (CHE-0619339) and mass spectrometry (CHE-0443618) facilities at Boston University are supported by the National Science Foundation. The authors are grateful to A. Phillips, J. Porco and P. Wipf for helpful suggestions regarding this manuscript, and to F. Meschini for preliminary studies.

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C.D. performed the experiments. All authors conceived and designed the experiments, analysed the data, contributed to discussions and wrote the manuscript.

Correspondence to Corey R. J. Stephenson.

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The authors declare no competing financial interests.

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Dai, C., Narayanam, J. & Stephenson, C. Visible-light-mediated conversion of alcohols to halides. Nature Chem 3, 140–145 (2011) doi:10.1038/nchem.949

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