Synthesis of indoles through acceptorless dehydrogenative coupling catalyzed by nickel on silica-alumina

The high atom-economical formation of indoles from anilines and diols was described with affordable and easy to handle Ni/SiO2-Al2O3. After optimization, 2,3-dimethylindole was isolated with an excellent 98% yield in neat conditions. The scope of the reaction was studied and 13 indoles were isolated in 16-80% yields. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

A high atom-economical method for the formation of indoles from anilines and diols was successfully achieved using affordable and easy-to-handle Ni/SiO2-Al2O3. The reaction resulted in excellent yields of 2,3-dimethylindole with good scope and versatility.