Mechanistic studies of organocopper reactions

Abstract Many different types of organocopper reagents have been used in organic synthetic procedures and the variety of reactions observed is also extensive. This synthetic efficiency has naturally promoted further extension and refinement and has also generated the inevitable questions regarding the mechanisms of these reactions. Mechanistic investigations in this area have therefore been undertaken for some considerable time and are aimed at rationalizing and directing further synthetic developments as well as increasing fundamental knowledge of a set of chemical reaction processes. It should be noted that the chemical behaviour of one type of organocopper reagent is sometimes very different from that of another reagent, and also organocopper reagents often react differently in different solvents. Hence, for practical application to a desired transformation it is often necessary to examine several types of organocopper reagents under different reaction conditions in order to attain the optimum reaction efficiency. The wide variation in the types of organocopper reagents and reaction conditions successfully used in synthesis creates many opportunities for mechanistic investigation. However, in many cases reaction parameters uncovered for one reaction-reagent combination may not be applicable to another, apparently related, system.