Covalent Organic Framework Decorated with Vanadium as a New Platform for Prins Reaction and Sulfide Oxidation

Abstract

Chemical functionalization or docking of transition-metal ions in covalent organic frameworks (COFs) is of importance for calibrating properties and widening potential applications. In this work, we demonstrate the successful decoration of COF with vanadium as exemplified in the context of post-synthetically modifying two-dimensional COF that features eclipsed stacking structure, large pores, hydroxyl functionalities, high thermal and chemical stability using vanadyl acetylacetonate. The potent catalytic behavior of vanadiumdecorated COF was systematically investigated in the reactions of Prins condensation and sulfide oxidation, which revealed its excellent catalytic performances in terms of efficacious activity, preservation of framework crystallinity and reusability. Our work not only contributes the first ever report of vanadium-decorated COF-catalyzed Prins reaction and sulfide oxidation but paves a new way for docking COF with metals for a broad range of applications.

Imine‐Based Covalent Organic Frameworks as Photocatalysts for Metal Free Oxidation Processes under Visible Light Conditions

“…Moreover, the overoxidation process to sulfone has been also described as a limitation to be overcome. However, although the use of materials in the sulfoxidation reactions has been explored, [14][15][16][17][18][19][20][21][22] several limitations have been frequently described, such as the use of high powered light energy (> 150 W), [14] materials decorated with toxic metals, [16] non-green solvents and moderate recyclability. [8][9][10][11][12][13] Therefore, an alternative oxidation for the use of peracids and peroxides is the application of gaseous reagents that allows the development of greener processes by reducing the waste from purification, because excess of gas can be easily removed from the reaction.…”

“…[6] In the last decade, photocatalysis has emerged as a powerful solution for the activation of different molecules such as oxygen. [16] Overcoming such drawbacks would be highly desirable in order to achieve a green process. Although in most cases the use of oxygen for the oxidation of sulfides has been carried out with homogeneous systems, the use of heterogeneous materials, especially those containing porosity in their structure, seems one of the most logical approaches for the use of gases in catalysis.…”

Covalent Organic Frameworks: Chemical Approaches to Designer Structures and Built‐In Functions

“…The vanadium‐decorated VO‐TAPT‐2,3‐DHTA COF (Figure d) serves as a Lewis acid to catalyze the Prins reaction between β‐pinene and formaldehyde in 69 % yield. The same COF oxidizes aliphatic and aromatic sulfides to sulfoxides in the presence of 70 % tert ‐butylhydroperoxide (TBHP), with up to 99 % conversion . The coupling of arylboronic acids with amines (Chan–Lam coupling) can be promoted by a catalytic amount of a copper‐impregnated imide COF (Figure e; Cu@PI‐COF).…”

Recent Advances in Covalent Organic Frameworks for Catalysis

“…[73][74][75][76][77] Generally,i ncorporating nitrogen-containingm olecular units, such as amine, imine and triazine groups, within at unable COF could facilitatet ol ock metal active sites. [73][74][75][76][77] Generally,i ncorporating nitrogen-containingm olecular units, such as amine, imine and triazine groups, within at unable COF could facilitatet ol ock metal active sites.…”