The coupling reaction of substituted toluenes themselves and the cross-coupling reaction of substituted toluene and aromatic in the presence of bromine in anhydrous CCl4 under irradiation lead to diphenylmethanes with moderate to good yields. The methylene moiety in diphenylmethanes comes from the toluene with fewer electron-donating groups, and regioselectivity was observed.
The coupling reaction of substituted toluenes themselves and the cross-coupling reaction of substituted toluene and aromatic in the presence of bromine in anhydrous CCl4 under irradiation lead to diphenylmethanes with moderate to good yields. The methylene moiety in diphenylmethanes comes from the toluene with fewer electron-donating groups, and regioselectivity was observed.