potassium carbonate in acetonitrile T=50°C; 18 h;

sodium in ethanol

copper dichloride in tetrahydrofuran; N,N-dimethyl-formamide Kinetics; byproducts: CuCl, CO; injection of a THF soln. of Cr-complex to a DMF soln. containing unhydrated CuCl2 in a UV cell at 25°C under anaerobic conditions; monitoring by UV spectroscopy at 315 nm;