Catalytic asymmetric synthesis of secondary nitriles via stereoconvergent Negishi arylations and alkenylations of racemic α-bromonitriles
- Creators
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Choi, Junwon
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Fu, Gregory C.
Abstract
The first method for the stereoconvergent cross-coupling of racemic α-halonitriles is described, specifically, nickel-catalyzed Negishi arylations and alkenylations that furnish an array of enantioenriched α-arylnitriles and allylic nitriles, respectively. Noteworthy features of this investigation include: the highly enantioselective synthesis of α-alkyl-α-aryl nitriles that bear secondary α-alkyl substituents; the first examples of the use of alkenylzinc reagents in stereoconvergent Negishi reactions of alkyl electrophiles; demonstration of the utility of a new family of ligands for asymmetric Negishi cross-couplings (a bidentate bis(oxazoline), rather than a tridentate pybox); in the case of arylzinc reagents, carbon–carbon bond formation at a remarkably low temperature (−78 °C), the lowest reported to date for an enantioselective cross-coupling of an alkyl electrophile; a mechanistic dichotomy between Negishi reactions of an unactivated versus an activated secondary alkyl bromide.
Additional Information
Copyright © 2012 American Chemical Society. Received: April 10, 2012. Article ASAP May 21, 2012. Published In Issue June 06, 2012. Support has been provided by the National Institutes of Health (National Institute of General Medical Sciences, grant R01-GM62871) and the Kwanjeong Educational Foundation (fellowship to J.C.). We thank Dr. Ashraf Wilsily for assistance in the preparation of substrates. The authors declare no competing financial interest. Supporting Information: Experimental procedures and compound characterization data. This material is available free of charge via the Internet at http://pubs.acs.org.Attached Files
Accepted Version - nihms379312.pdf
Supplemental Material - ja303442q_si_001.cif
Supplemental Material - ja303442q_si_002.cif
Supplemental Material - ja303442q_si_003.pdf
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Additional details
- PMCID
- PMC3415582
- Eprint ID
- 48840
- Resolver ID
- CaltechAUTHORS:20140825-100734890
- NIH
- R01-GM62871
- Kwanjeong Educational Foundation
- Created
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2014-08-25Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field