Copper (low valent)
See also copper hydride.
The reduction of a series of alkyl sulfonates to the corresponding hydrocarbons was efficiently performed using a reducing system composed of CuCl2·2H2O, an excess of lithium sand and a catalytic amount of 4,4′-di-tert-butylbiphenyl (DTBB), in tetrahydrofuran at room temperature. The process was also applied to enol and dienol triflates affording alkenes and dienes, respectively.
G. Radivoy, F. Alonso, Y. Moglie, C. Vitale, M. Yus, Tetrahedron, 2005, 61, 3859-3864.