REDUCTIVE COUPLING OF ORGANIC HALIDE USING HYDRAZINE AND A PALLADIUM AMALGAM CATALYST - II. HOMOCOUPLING OF HALOARENE WITH ARLHYDRAZINE.

Article abstract of DOI:10.1246/bcsj.56.1113

The function of palladium chloride in the reaction of an arylhydrazine with a haloarene was found to differ from those of other metal salts; palladium chloride was reduced with arylhydrazine, and the palladium metal produced was again oxidized with haloarene to give palladium halide. Thus the reductive coupling of haloarene occurred in the presence of a catalytic amount of palladium chloride. Addition of mercury(II) chloride promoted this reaction. The reaction of o-, m-, and p-bromotoluene with the corresponding tolylhydrazine gave the corresponding bitolyl in 99, 112, and 115% yield, respectively, based on the haloarene.