Reduction of chloroacetophenone using the sulfoximine borane

The toluene was distilled from sodium and benzophenone and then stored over activated molecular sieves. 

Chloroacetophenone is toxic and needs to be manipulated using gloves and eye protection in a well-ventilated fume-hood. 

A 50 mL round-bottomed flask equipped with a magnetic stirrer was dried overnight at 150 °C and placed under vacuum and then flushed with nitrogen. 

The flask was charged with the sulfoximine catalyst (68 mg) and dry toluene (4mL). To this white suspension was added borane dimethylsulfide (1.2 mL). The mixture became clear with the evolution of hydrogen. 

After 15 minutes a solution of chloroacetophenone (310 mg) in dry toluene (2mL) was added via a syringe pump over a period of 3 hours at room temperature. 

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