10.1002/ejoc.202000565
European Journal of Organic Chemistry
COMMUNICATION
and produces product 3 along with the regeneration of reactive
cobalt species I.
the Korea government (Ministry of Education) (No.
2019R1A6C1010042).
Keywords: C–H alkylation • Co(III)-catalyst • phenylethyl group •
unactivated alkenes
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Scheme 5. Plausible reaction mechanism.
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In conclusion, we have achieved direct C–H alkylation with
styrenes using cobalt(III) catalyst, which produced regioselective
linear and mono-diarylethane products. This method extended
the scope of Cp*Co(III)-catalyzed C–H alkylation, and provided a
simple, practical, and atom-economical way to construct
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subjected to further C–H bond functionalizations to demonstrate
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Experimental Section
General procedure for C–H alkylation
An oven-dried Schlenk tube was evacuated and flushed with argon three times.
Then, it was evacuated and transferred to the glovebox. AgSbF6 (10.3 mg,
0.03 mmol) was added, and the Schlenk tube was transferred to the fume hood
and connected to the argon atmosphere. Cp*Co(CO)I2 (4.8 mg, 0.01 mmol), 2-
aryl pyridine 1 (0.2 mmol, 1.0 equiv), alkene 2 (0.36 mmol, 1.8 equiv), pivOH
(30.6 mg, 0.3 mmol), and 2,2,2-trifluoroethanol (TFE) (2.0 mL) were added. The
resulting mixture was sealed with a Teflon-lined cap and stirred at 100 ℃ for
24 h. The solvent was evaporated under vacuum and the desired product 3 was
obtained by column chromatography using an appropriate eluent.
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Acknowledgements
This work was financially supported by National Research
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Foundation
(NRF-2017R1C1B2004174,
NRF-
2020R1A4A2002831) and Korea Basic Institute (KBSI) National
Research Facilities & Equipment Center (NFEC) grant funded by
4
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