An efficient synthesis of N-substituted indoles from indoline/indoline carboxylic acid via aromatization followed by C–N cross-coupling reaction by using nano copper oxide as a recyclable catalyst

• Published in: Tetrahedron letters Vol. 53; no. 24; pp. 3061 - 3065
• Main Authors: Reddy, K. Harsha Vardhan, Satish, G., Ramesh, K., Karnakar, K., Nageswar, Y.V.D.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 13-06-2012
• Subjects: CuO nanoparticles; C–N cross-coupling; Indoline/indoline carboxylicacid; N-substituted indoles; Recyclability; Indoline/indoline carboxylicacid; N-substituted indoles; Recyclability; C–N cross-coupling; CuO nanoparticles
• ISSN: 0040-4039; 1873-3581
• DOI: 10.1016/j.tetlet.2012.04.012

A new and elegant protocol for the synthesis of 1-substituted indoles was developed via aromatization of indoline/indoline carboxylic acid followed by C–N cross-coupling with various aryl halides in the presence of nano CuO as a recyclable catalyst, Cs2CO3 as a base in DMSO at 80°C. 1-Substituted indoles were obtained in good to excellent yields and the catalytic system can be recycled up to four cycles without loss of catalytic activity.