Highly Reactive Form of Copper and Reagents Thereof

Patent Highly Reactive Form of Copper and Reagents Thereof 

US Patent 5,490,952 (February 13, 1996) Assignee University of Nebraska Utility Organo Copper Reagents 

Lithium (8.46 mmol) and naphthalene (10.1 mmol) were mixed with 15 ml THF, stirred 2 hours, and then cooled to — 100°C. In a separate reaction vessel, CuCN (8.0 mmol) and LiBr (17.27 mmol) in 5 ml THF were stirred until the Cu(I) salt dissolved. The solution was cooled to —40°C and transferred into lithium naphthalide using a cannula and the mixture stirred 5 minutes. The catalytic agent was ready for immediate use. 

The product from Step I was warmed to —35°C, charged with ethyl 4-bromobutyrate (1.95 mol), stirred 10 minutes, and benzoyl chloride (3 equiv.) added via syringe at —35°C. The solution was stirred 30 minutes, quenched with NH4CI, and the product isolated by flash chromatography techniques. 

A second method for preparing the Step 1 zerovalent copper reagent was also provided by the author and described below  

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