Organophotocatalysed synthesis of 2-piperidinones in one step via [1?+?2?+?3] strategy

Six-membered N-containing heterocycles, such as 2-piperidinone derivatives, with diverse substitution patterns are widespread in natural products, drug molecules and serve as key precursors for piperidines. Thus, the development of stereoselective synthesis of multi-substituted 2-piperidinones are attractive. However, existing methods heavily rely on modification of pre-synthesized backbones which require tedious multi-step procedure and suffer from limited substitution patterns. Herein, an organophotocatalysed [1 + 2 + 3] strategy was developed to enable the one-step access to diverse substituted 2-piperidinones from easily available inorganic ammonium salts, alkenes, and unsaturated carbonyl compounds. This mild protocol exhibits exclusive chemoselectivity over two alkenes, tolerating both terminal and internal alkenes with a wide range of functional groups. The synthesis of 2-piperidinone derivatives remains challenging. Here, the authors develop an organophotocatalysed [1 + 2 + 3] strategy to enable the one-step access to diverse 2-piperidinones from ammonium salts, alkenes, and unsaturated carbonyl compounds.

Automated summary

In this study, an organophotocatalytic strategy was developed for the one-step synthesis of diverse 2-piperidinones. This mild and efficient protocol exhibits exclusive chemoselectivity and broad substrate tolerance.