Useful Copper Reagent for Coupling Reactions

CuTC (1) is used as a useful copper reagent for various reactions in organic synthesis. For example, Stille cross-coupling¹⁾ and Ullmann coupling²⁾ efficiently proceed at room temperature by using 1. In Liebeskind-Srogl cross-coupling, thiol esters react with boronic acids under mild conditions by using the palladium catalyst and 1, affording the corresponding unsymmetrical ketones.³⁾ This reaction can be applied to highly functionalized and base-sensitive compounds, because it proceeds under nonbasic reaction conditions.