Nickel-Catalyzed Coupling Reactions of Alkyl Electrophiles, Including Unactivated Tertiary Halides, To Generate Carbon–Boron Bonds
- Creators
- Dudnik, Alexander S.
-
Fu, Gregory C.
Abstract
Through the use of a catalyst formed in situ from NiBr2·diglyme and a pybox ligand (both of which are commercially available), we have achieved our first examples of coupling reactions of unactivated tertiary alkyl electrophiles, as well as our first success with nickel-catalyzed couplings that generate bonds other than C–C bonds. Specifically, we have determined that this catalyst accomplishes Miyaura-type borylations of unactivated tertiary, secondary, and primary alkyl halides with diboron reagents to furnish alkylboronates, a family of compounds with substantial (and expanding) utility, under mild conditions; indeed, the umpolung borylation of a tertiary alkyl bromide can be achieved at a temperature as low as −10 °C. The method exhibits good functional-group compatibility and is regiospecific, both of which can be issues with traditional approaches to the synthesis of alkylboronates. In contrast to seemingly related nickel-catalyzed C–C bond-forming processes, tertiary halides are more reactive than secondary or primary halides in this nickel-catalyzed C–B bond-forming reaction; this divergence is particularly noteworthy in view of the likelihood that both transformations follow an inner-sphere electron-transfer pathway for oxidative addition.
Additional Information
© 2012 American Chemical Society. Received: April 27, 2012. Published: June 6, 2012. Support has been provided by the National Institutes of Health (National Institute of General Medical Sciences, grant R01-GM62871). We thank Dr. Ashraf Wilsily for experimental assistance. The authors declare no competing financial interest.Attached Files
Accepted Version - nihms383249.pdf
Supplemental Material - ja304068t_si_001.pdf
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Additional details
- PMCID
- PMC3384763
- Eprint ID
- 102846
- Resolver ID
- CaltechAUTHORS:20200428-095144864
- NIH
- R01-GM62871
- Created
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2020-04-29Created from EPrint's datestamp field
- Updated
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2021-11-16Created from EPrint's last_modified field