Preparation of Highly Active Manganese Mn

To the mixture of lithium (4.4 mmol), naphthalene (0.4 mmol), and manganese halides (2 mmol) was added via syringe freshly distilled THF (10 ml) at rt, and 

Typical Preparation of Benzylic Manganese Halides and Their Coupling Reactions with Benzoyl Chlorides to Give Ketones (2a-2l) 

Typical Procedure for the Cross-Coupling Reactions of Benzyl Manganese Mesylates 

Benzyl mesylate (9 mmol) was added via a syringe to the slurry of active manganese (lOmmol) being stirred in THF (10ml) at rt. The resulting mixture was stirred at rt for 20 min. The reaction was monitored by gas chromatography. 

After the completion of the oxidative addition, the mixture was cooled to 0°C. 1,2-Dibromoethane was added to the mixture at this temperature, and the mixture was stirred for 5 min. Benzoyl chloride was added to the resulting mixture at rt. After being stirred for 30 min, the mixture was quenched with 2M HCl solution and extracted with diethyl ether. The combined organic layers were washed with NaHCOs, NasSsOs, and brine, dried over anhydrous MgS04, and concentrated using a rotary evaporator. Flash column chromatography (ethyl acetate-hexanes) afforded the corresponding ketones. 

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