DIRECT FORMATION OF HIGHLY FUNCTIONALIZED ALLYLIC ORGANOCOPPER REAGENTS FROM ALLYLIC CHLORIDES AND ACETATES

The direct formation of highly functionalized allylic organocopper reagents has been carried out using a highly active form of zerovalent copper (Cu*). The cold-temperature reduction of CuCN.nLiX complexes by lithium naphthalenide in THF under an argon atmosphere produces the Cu* complex, which reacts rapidly with primary and secondary allyl chlorides at -100-degrees-C with little homocoupling. Allyl, methallyl, and crotyl acetates also oxidatively add with Cu* at low temperatures to afford the corresponding organocopper reagent. Significantly, the allyl chlorides can contain a wide array of functional groups including ketones, alpha,beta-unsaturated ketones, epoxides, alkyl acetates, esters, alkyl chlorides, nitriles, and carbamates. The cross-coupling of the highly functionalized allylic organocopper reagents with various electrophiles proceeds in excellent yields.