From Dinitrogen to N-Containing Organic Compounds: Using Li2 CN2 as a Synthon

Abstract

Through the synergies of a heterogeneous synthetic approach and a homogeneous synthetic methodology, N-containing organic compounds can be synthesized via activated N-containing species prepared from N₂ gas and suitable carbon sources. From N₂ , carbon, and LiH, we have previously succeeded in the high-yield preparation of Li₂ CN₂ as the activated N-containing species. In this work, we applied Li₂ CN₂ as a novel synthetic synthon for constructing N-containing organic compounds. A series of reaction models, including a substitution reaction, cycloaddition reaction, and transition metal-catalyzed coupling reaction, were successfully performed using Li₂ CN₂ under mild conditions. Various valuable cyanamides, carbodiimides, N-aryl cyanamides and 1,2,4-triazole derivatives were readily synthesized in moderate to excellent yields. With this method, the ¹⁵ N-labeled products, including oxazolidine derivatives with anti-cancer activity, could also be facilely prepared from ¹⁵ N₂ gas.

Keywords: Cycloaddition; Dinitrogen; Heterocycles; Labeled Compounds; Lithium.