Sustainable multicomponent indole synthesis with broad scope

The most preferred heterocyclic indole core was de novo assembled by an innovative 2-step reaction from inexpensive and broadly available anilines, glyoxal dimethyl acetal, formic acid and isocyanides involving an Ugi multicomponent reaction followed by an acid induced cyclization. As opposed to many other indoles syntheses, our method delivers under mild and benign conditions using ethanol as solvent and no metal catalyst. The scope of the reactions was scouted and 20 derivatives are described.

Automated summary

In this study, a preferred heterocyclic indole core is synthesized by an innovative 2-step reaction, resulting in the synthesis of 20 derivatives. The method utilizes ethanol as a solvent under mild conditions and does not require a metal catalyst.