Copper-Catalyzed Cascade Denitrogenative Transannulation/Hydrolyzation of 3-Aminoindazoles toward 2,2-Disubstituted Indanones.

A copper-catalyzed cascade denitrogenative transannulation/hydrolyzation of 3-aminoindazoles with N-(2-methylallyl)anilines was developed, affording a variety of 2-(aminomethyl)-2-methyl-indanones in moderate to good yields. 2-Cyanophenyl radical, which generated from oxidative denitrogenation of 3-aminoindazole, was proved as the reaction intermediate. This reaction features, along with the ready availability of starting materials, a cascade cleavage of two C-N bonds and construction of two C-C bonds in one pot.