COMMUNICATIONS
References
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plex (B) by manganese, a similar procedure leads to
a cobalt-bialkyl complex (F). Finally a reductive elim-
ination gives the desired homocoupling product and
regenerates the catalyst.
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À
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Experimental Section
General Procedure
To a solution of CoBr2 (10 mol%, 0.25 mmol, 55 mg) and
manganese powder (3.8 equiv., 9.5 mmol, 500 mg) in
CH3CN (3 mL) was added at room temperature the alkyl
halide (2.5 mmol). Manganese powder was activated by
traces of trifluoroacetic acid (50 mL) and the mixture was
then stirred at room temperature for 5 min until smoke dis-
appeared. At this time, pyridine or 2-picoline (0.5 mL) was
added and the mixture was stirred at 508C until the alkyl
halide was consumed (3 to 6 h). The mixture was then
quenched with a solution of 2M HCl (30 mL) and was
stirred vigorously until the layers turned clear. The solution
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Acknowledgements
We thank the Ministꢀre de l’Enseignement Supꢁrieur et de la
Recherche (PhD grants to Y. C. and X. Q.). This work was
supported by CNRS and Ecole Polytechnique.
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