Three-component radical homo Mannich reaction

Aliphatic amine, especially tertiary aliphatic amine, is one of the most popular functionalities found in pharmaceutical agents. The Mannich reaction is a classical and widely used transformation for the synthesis of beta -amino-carbonyl products. Due to an ionic nature of the mechanism, the Mannich reaction can only use non-enolizable aldehydes as substrates, which significantly limits the further applications of this powerful approach. Here we show, by employing a radical process, we are able to utilize enolizable aldehydes as substrates and develop the three-component radical homo Mannich reaction for the streamlined synthesis of gamma -amino-carbonyl compounds. The electrophilic radicals are generated from thiols via the desulfurization process facilitated by visible-light, and then add to the electron-rich double bonds of the in-situ formed enamines to provide the products in a single step. The broad scope, mild conditions, high functional group tolerance, and modularity of this metal-free approach for the synthesis of complex tertiary amine scaffolds will likely be of great utility to chemists in both academia and industry. Due to the ionic nature of its mechanism, the Mannich reaction can only use non-enolizable aldehydes as substrates. Here, the authors expand the scope of the classical Mannich reaction to enolizable aldehydes by employing a radical process resulting in a streamlined synthesis of gamma -amino-carbonyl compounds.

Automated summary

The authors expanded the scope of the classical Mannich reaction to enolizable aldehydes by employing a radical process, resulting in a streamlined synthesis of gamma -amino-carbonyl compounds.