The reactions of 2-[(dimethylamino)methyl]phenylcopper and -lithium tetramer with cuprous and cupric halides

Abstract

2-[(Dimethylamino)methyl]phenylcopper tetramer (R{4}Cu{4}) forms a red 11 complex (RCu - CuBr){n} with cuprous bromide. The 11 interaction of 2-[(dimethylamino)methyl]phenylcopper with cupric halides results in the formation of the dimer R@?R, the 2-halo-substituted benzylamine R-Halide and minor amounts of N, N-dimethylbenzylamine RH. The formation of these products can be explained on the basis of an intramolecular electron-transfer redox reaction taking place in innersphere activated complexes of the type R{4}Cu{3}Cu - - - X - - - Cu}I{}I{X(Cu}I{}I{X{2}){n}{-}{1}. The course of the metathesis reaction of 2-[(dimethylamino)methyl]phenyllithium with cuprous bromide depends on the order of addition of the reactants. Reversed addition (RLi to CuBr) results in the formation of an inseparable mixture of complexes of the type (RCu){x}- (CuBr){y}. Upon addition of CuBr to RLi the uncomplexed organocopper compound R{4}Cu{4} is formed.