Alkaline carbons as effective catalysts for the microwave-assisted synthesis of N-substituted-gamma-lactams

The selective construction of new CC or Cheteroatom bonds is frequently the fundamental step in the synthesis of derivatives with high added value. In particular, molecules with CN bonds are of great interest due to their widespread use and intrinsic importance. Of the large number of organic compounds with useful biological activity, organic compounds with CN bonds are among the most prominent. For instance, the nitrogenated gamma-lactamic heterocycles are the basic structures of many substances used as intermediates in the synthesis of important compounds with pharmacological properties such as psychotropics and antihypertensives as well as others with biological properties. In the present work, we reported for the first time an efficient and eco-friendly alternative to obtain N-substituted-gamma-lactams by carbon–nitrogen coupling of 2-pyrrolidinone and 1-heptanal assisted by microwave irradiation, over activated alkali-Norit carbon catalysts in solvent-free conditions.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (92 K)Download as PowerPoint slideHighlights► Synthesis of N-substituted-gamma-lactams. ► Substantial enhancing effects in the reaction activated by microwave irradiation. ► Microwave activation and alkaline carbon catalysts offers interesting prospects. ► Excellent yields under mild reaction conditions. ► This process can be also generalized for the production of similar fine chemicals.