The indene is an important class of compounds that exists widely in nature and has numerous applications in medicine. Consequently, a number of approaches to the synthesis of the indene ring system have been developed.

Researchers at Lanzhou University and Lanzhou Institute of Chemical Physics (LICP), Chinese Academy of Sciences (CAS), have developed a mild and efficient CuI catalytic method for the synthesis of indene. A variety of secondary amines undergo this process, giving the desired products in moderate to good yields.

The work has received support from National Science Foundation and the findings have been published in Org. Biomol. Chem.(Org. Biomol. Chem., 2012, 10, 3636–3641).

Optimization of the copper-catalyzed three-components coupling and cyclization reaction of 2-(2-ethylphenyl)malonate, disopropylamine and paraformaldehyde