DIRECT FORMATION AND REACTION OF THIENYL-BASED ORGANOCOPPER REAGENTS

The preparation of a highly reactive zerovalent copper complex by the direct reduction of lithium (2-thienylcyano)cuprate with preformed lithium naphthalenide is described. This active copper species oxidatively adds to carbon-halogen bonds to form organocopper reagents. The ability to directly form the organocopper reagent from organic halides and active copper allows for the incorporation of a wide variety of functionalities to be present in the organic halides and the organocopper reagents. Significantly, this formulation of active copper was able to oxidatively add to allyl chlorides and acetates at low temperatures to allow the direct formation of allylic organocopper reagents without Wurtz-type homocoupling. These functionalized organocopper compounds are able to undergo a variety of reactions, such as cross-coupling with acid chlorides, 1,4-conjugate addition with alpha,beta-unsaturated carbonyl compounds, and intermolecular and intramolecular epoxide-opening reactions. Subsequently, this copper species avoids the use of phosphine ligands affording the product isolation much more convenient than with phosphine-based organocopper reagents.