Synthesis of arylamines and N-heterocycles by direct catalytic nitrogenation using N2

Kai Wang,Hua-Yi Fang,Zhang-Jie Shi,Dan-Dan Zhai,Zi-Hao Deng,Si-Jun Xie

doi:10.1038/s41467-020-20270-5

Abstract

Ammonia and nitric acid are two key platform chemicals to introduce nitrogen atoms into organic molecules in chemical industry. Indeed, nitric acid is mostly produced through the oxidation of ammonia. The ideal nitrogenation would involve direct use of dinitrogen (N2) as a N source to construct N-containing organic molecules. Herein, we report an example of direct catalytic nitrogenation to afford valuable diarylamines, triarylamines, and N-heterocycles from easily available organohalides using dinitrogen (N2) as the nitrogen source in a one-pot/two-step protocol. With this method, 15N atoms are easily incorporated into organic molecules. Structurally diversified polyanilines are also generated in one pot, showing great potential for materials chemistry. In this protocol, lithium nitride, generated in situ with the use of lithium as a reductant, is confirmed as a key intermediate. This chemistry provides an alternative pathway for catalytic nitrogenation to synthesize highly valuable N-containing chemicals from dinitrogen.

Highlights

Ammonia and nitric acid are two key platform chemicals to introduce nitrogen atoms into organic molecules in chemical industry
Despite some synthetic cycles having been reported for the synthesis of N-containing molecules[23,24,25,26], to the best of our knowledge, catalytic transformation to carry out direct nitrogenation of organic molecules from dinitrogen (N2) has not been approached up to date
The use of alkali or alkalineearth metals to in situ reduce dinitrogen may be a good choice. This design would provide an efficient approach to N-containing molecules from dinitrogen by avoiding the tedious and energyconsuming procedures required by ammonia and nitric acid as platform chemicals

Summary

Introduction

Ammonia and nitric acid are two key platform chemicals to introduce nitrogen atoms into organic molecules in chemical industry. Lithium nitride, generated in situ with the use of lithium as a reductant, is confirmed as a key intermediate This chemistry provides an alternative pathway for catalytic nitrogenation to synthesize highly valuable N-containing chemicals from dinitrogen. Aryllithium (ArLi) was shown as an interesting starting point for direct nitrogenation with dinitrogen via Ti catalysis to produce aniline derivatives (Fig. 1c), representing the first successful catalytic transformation in amine synthesis, albeit the efficiency was not sufficient for applications[34,35]. The use of alkali or alkalineearth metals to in situ reduce dinitrogen may be a good choice This design would provide an efficient approach to N-containing molecules from dinitrogen by avoiding the tedious and energyconsuming procedures required by ammonia and nitric acid as platform chemicals

Objectives

Methods

Results

Conclusion