Organic Chemistry Portal



Mild and efficient cyclization reaction of 2-ethynylaniline derivatives to indoles in aqueous medium

Kou Hiroya*, Shin Itoh and Takao Sakamoto

*Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba-ku, Sendai 980-8578, Japan, Email:

K. Hiroya, S. Itoh, T. Sakamoto, Tetrahedron, 2005, 61, 10958-10964.

DOI: 10.1016/j.tet.2005.08.098


A copper(II)-catalyzed cyclization of 2-ethynylaniline derivatives to indoles can be carried out in a mixture of H2O and MeOH in the presence of 1-ethylpiperidine at room temperature. A catalyst recycling reaction system was established.

see article for more examples

Key Words

Indoles, Copper(II) salt, 2-Ethynylaniline, Cyclization reaction

ID: J72-Y2005-3150