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. 2009 Mar 11;131(9):3160-1.
doi: 10.1021/ja809382c.

Efficient boron-copper additions to aryl-substituted alkenes promoted by NHC-based catalysts. enantioselective Cu-catalyzed hydroboration reactions

Yunmi Lee  1 , Amir H Hoveyda
Affiliations

Efficient boron-copper additions to aryl-substituted alkenes promoted by NHC-based catalysts. enantioselective Cu-catalyzed hydroboration reactions

Yunmi Lee et al. J Am Chem Soc. .

Abstract

A Cu-catalyzed method for efficient boron-copper addition processes involving acyclic and cyclic disubstituted aryl olefins are reported. Reactions are promoted with 0.5-5 mol % of a readily available N-heterocyclic carbene (NHC) complex; the presence of MeOH promotes in situ protonation of the C-Cu bond and leads to efficient catalyst turnover, constituting a net Cu-catalyzed hydroboration process. Reactions proceed in >98:<2 site selectivity and furnish secondary organoborane isomers that complement those obtained through reactions of boron-hydride reagents or by Rh- or Ir-catalyzed hydroborations (benzylic secondary C-B bonds). Initial observations regarding processes catalyzed by chiral NHC complexes, delivering products in up to 99:1 enantiomeric ratio, are disclosed.

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Figures

Scheme 1
Scheme 1
Cu–Catalyzed Hydroboration of Allylic Esters, Ethers and Alcohols
Scheme 2
Scheme 2
Cu–Catalyzed Enantioselective Hydroboration Reactionsa aSee SI for experimental details; oxidation conditions for 14–16: H2O2, 2.0 N aqueous NaOH; MeOH not used for 16. >98:<2 site-selectivity in all cases.
See this image and copyright information in PMC

References

    1. For a review on catalytic enantioselective hydroboration, see: Carroll A-M, O’Sullivan TP, Guiry P. J. Adv. Synth. Catal. 2005;347:609–631.

    1. Glorious F, editor. N-Heterocyclic Carbenes in Transition Metal Catalysis. Berlin, Heidelberg: Springer-Verlag; 2007.
    1. Van Veldhuizen JJ, Campbell JE, Giudici RE, Hoveyda AH. J. Am. Chem. Soc. 2005;127:6877–6882. - PubMed
    2. Larsen AO, Leu W, Nieto-Oberhuber C, Campbell JE, Hoveyda AH. J. Am. Chem. Soc. 2004;126:11130–11131. - PubMed
    3. Brown MK, May TL, Baxter CA, Hoveyda AH. Angew. Chem., Int. Ed. 2007;46:1097–1100. - PubMed

    1. For Rh-catalyzed enantioselective hydroborations of disubstituted styrenes (to afford predominantly benzylic alcohols), see: Doucet H, Fernandez E, Layzell TP, Brown JM. Chem. Eur. J. 1999;5:1320–1330.

    1. Laitar DS, Müller P, Sadighi JP. J. Am. Chem. Soc. 2005;127:17196–17197. - PubMed
    2. Laitar DS, Tsui EY, Sadighi JP. Organometallics. 2006;25:2405–2408.

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