N-formylation of amines with CO2 by using Zr-based metal-organic frameworks: Contribution of defect sites of MOFs to N-formylation

• Published in: Applied catalysis. A, General General, 2023-06, Vol.659, p.119170, Article 119170
• Main Authors: Yoo, Dong Kyu, Jhung, Sung Hwa
• Format: Article
• Language: English
• Subjects: Carbon dioxide; Defect site; Metal-organic framework; N-formylation
• ISSN: 0926-860X; 1873-3875
• DOI: 10.1016/j.apcata.2023.119170

N-formylation of amines (NFAs) like N-methylaniline and morpholine with CO2 was done under mild condition (0.1 MPa, 30 °C) in the presence of PhSiH3 as a reductant by using Zr-based MOFs like MOF-808 s (with various defect concentrations), UiO-66, and UiO-67. Preparing useful N-formamides from amines is one of the attractive ways to utilize CO2. The yield of N-methylformanilide from N-methylaniline linearly increased with increasing the defect concentration of MOF-808. Moreover, the performance of MOF-808(6), with the highest defect sites, decreased with the elimination of defects. Amorphized MOF-808(6), with increased defects, showed an impressive performance in NFAs, although the porosity decreased much upon amorphization. Therefore, defect sites had a dominant role in the NFAs, especially in the adsorption or activation of carbamate-like intermediates and silane. Moreover, defective MOF-808(6), prepared in one step (without any functionalization), might be a competitive/recyclable catalyst for NFAs, especially under mild conditions. [Display omitted] •-N-formylation of amines with CO2 was done firstly with defective metal-organic frameworks.•-NFAs could be done under mild conditions (CO2 0.1 atm, 30 °C) by using defective MOFs.•-Yield of N-methylformanilide linearly increased with defect concentration of MOF-808.•-Defects were important in adsorption/activation of carbamate-like intermediates and silane.•-Defective MOFs, prepared in one step, can be a competitive/recyclable catalyst for NFAs.