A sustainable strategy for the visible-light-driven facile N-formylation of amines using a Co(ii)-embedded covalent organic framework as an efficient photocatalyst

Abstract

Nowadays, to tackle the increased greenhouse effect, the development of efficient porous adsorbents with the capacity for rapid atmospheric CO₂ uptake is one of the new concerns in environmental remediation. The photocatalytic N-formylation of amines through CO₂ reduction offers a green and sustainable approach for the utilization of greenhouse gas CO₂. In this regard, we have constructed a highly crystalline 2D imine-linked Co(II)-incorporated Tp-TH COF catalyst (namely, Co(II)@Tp-TH) with a band gap energy of 2.4 eV to serve as a stable and effective porous photocatalyst. Different characterization techniques have been employed to determine the structural and morphological features of the photocatalyst. Moreover, as a novel photocatalyst, Co(II)@Tp-TH exhibits excellent catalytic activity, selectivity and recyclability for the sustainable one-pot synthesis of N-formylated products from a variety of amines, with a maximum TON value of 114 under ambient CO₂ pressure in DMF/CH₃OH without the need for any reducing agents or co-catalyst. These findings illustrate the development of a new, environmentally preferable green approach for the photocatalytic synthesis of N-formamides, which are essential chemical feedstocks for the production of heterocyclic compounds, medicines, and biologically active compounds.