Asymmetric Intramolecular Alkylation of Chiral Aromatic Imines via Catalytic C-H Bond Activation

Anja Watzke; Rebecca M. Wilson; Steven J. O’Malley; Robert G. Bergman; Jonathan A. Ellman

doi:10.1055/s-2007-985593

LETTER

Asymmetric Intramolecular Alkylation of Chiral Aromatic Imines via Catalytic C-H Bond Activation

Anja Watzke, Rebecca M. Wilson, Steven J. O’Malley, Robert G. Bergman*, Jonathan A. Ellman*
Department of Chemistry and Division of Chemical Sciences, Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720, USA
Fax: +1(510)6427714; e-Mail: rbergman@berkeley.edu; e-Mail: jellman@berkeley.edu;

Abstract

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Abstract

The asymmetric intramolecular alkylation of chiral aromatic aldimines, in which differentially substituted alkenes are tethered meta to the imine, was investigated. High enantioselectivities were obtained for imines prepared from aminoindane derivatives, which function as directing groups for the rhodium-catalyzed C-H bond activation. Initial demonstration of catalytic asymmetric intramolecular alkylation also was achieved by employing a sterically hindered achiral imine substrate and catalytic amounts of a chiral amine.

Key words

C-H bond activation - asymmetric catalysis - transimination - cyclization - dihydrobenzofuran

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References

References and Notes

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