Copper chloride - tetramethylethylenediamine complex

Binaphthols are important as ligands for transition metal catalysts used in stereoselective syntheses. The oxidation of a suspension of powdered 2-naphthol in water with ferric chloride and air gives the corresponding binaphthol (4.42) in 95% yield. This is an improvement over homogeneous syntheses which are accompanied by quinone formation.199 The workup consists of filtration, washing with water, drying, and recrystallization from toluene. The reaction can also be run with a catalytic amount of inexpensive cop-per(II) sulfate on alumina to produce the binaphthol in 97% yield.200 A third paper reports 77-99% yields with 1 mol% of a tetramethylethylenediamine complex of copper hy-droxychloride as the catalyst.201... 

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