What is the latest catalytic system for acetic acid to participate in the C- H bond activation reaction?

Acetic acid involved in C- H bond activation reaction of the latest catalytic system is what?

In modern chemical production, C- H bond activation reaction has attracted much attention because of its high efficiency and selectivity. Such reactions typically involve breaking C- H bonds in the organic molecule, thereby introducing new functional groups. The balance between stability and reactivity of the C- H bond has always been a challenge for chemists. In recent years, acetic acid, as an efficient and environmentally friendly catalyst or promoter, has shown unique potential in C- H bond activation reactions. In this paper, the latest catalytic system and its application prospect of acetic acid participating in C- H bond activation reaction will be analyzed in detail.

1. C- H bond activation reaction background and challenges

C- H bond activation reaction has a wide range of applications in organic synthesis, fine chemicals and materials preparation. Conventional C- H bond activation methods generally rely on strong oxidizing agents or high temperature and high pressure conditions, which not only increase reaction costs, but may also burden the environment and equipment. Therefore, the development of efficient and sustainable catalytic system has become the focus of research.

In this context, acetic acid, as a green and renewable acidic substance, has attracted wide attention because of its excellent catalytic performance. Acetic acid can not only provide an acidic environment, but also promote the activation of C- H bonds through the cooperative action of functional groups. The biocompatibility and stability of acetic acid make it an ideal green catalyst choice.

2. Acetic acid in C- H bond activation reaction mechanism

Acetic acid (CH3COOH) in the C- H bond activation reaction mainly through the following three ways to play a role:

(1) Acid catalysis: The carboxyl functional group (-COOH) in the acetic acid molecule makes it more acidic (pKa ≈ 4.76). In an acidic environment, acetic acid can interact with the substrate or catalyst surface in the C- H bond reaction, thereby promoting the cleavage of the C- H bond. This acidic catalysis can reduce the activation energy of the reaction and increase the reaction rate.

(2) Coordination and stabilization: The molecular structure of acetic acid enables it to coordinate with the metal catalyst to form a stable complex. This coordination can not only enhance the dispersion of the catalyst, but also regulate the electronic structure of the catalyst, thereby improving the activation efficiency of the C- H bond.

(3) Template effect: The polar group of the acetic acid molecule can be combined with a specific site in the substrate molecule through hydrogen bonding or electrostatic interaction, which plays a template effect. This effect can guide the adsorption and reaction path of substrate molecules on the surface of the catalyst, thereby improving the selectivity of the reaction.

3. The latest catalytic system construction and application

In recent years, researchers have developed a variety of acetic acid-based catalytic systems for C- H bond activation reactions. The following are some representative systems:

(1) Metal-acetic acid composite catalytic system: The combination of metal catalysts (such as Cu, Fe, Ni, etc.) and acetic acid is one of the hotspots of current research. For example, Cu/Al₂ O₂ supported catalysts with the aid of acetic acid can efficiently activate C- H bonds to produce high value-added chemicals. This composite catalytic system not only has high activity, but also shows good reusability.

(2) oxide-acetic acid synergistic catalytic system: The combination of oxides (such as TiO₂, ZnO, etc.) with acetic acid is also an effective catalytic strategy. Oxygen defects and acidic sites on the oxide surface can interact with acetic acid molecules to form a synergistic effect. This catalytic system exhibits excellent selectivity and stability in C- H bond activation reactions.

(3) Organic ligand-acetic acid synergistic catalytic system: Catalytic systems combining organic ligands (such as porphyrins, crown ethers, etc.) with acetic acid have also made significant progress in recent years. By the steric hindrance effect of organic ligands and the acidity of acetic acid, this system realizes the efficient regulation of the C- H bond activation reaction.

4. Challenges and future directions

Although the catalytic performance of acetic acid in the C- H bond activation reaction has been verified to a certain extent, there are still some unresolved problems:

(1) Further elucidation of the reaction mechanism: At present, the specific mechanism of acetic acid in the C- H bond activation reaction is still not completely clear. In-depth study of its mechanism of action will help to optimize the design of the catalytic system.

(2) Enhancement of selectivity and stability: Some catalytic systems still have room for improvement in terms of reaction selectivity and cycle stability. The development of more efficient and stable acetic acid-based catalytic system is the key direction of future research.

(3) the promotion of industrial applications: At present, most catalytic systems based on acetic acid are still in the laboratory research stage. How to realize its large-scale application in industrial production still needs further technological breakthroughs.

5. Summary and Prospect

As a green and renewable accelerator, acetic acid shows a broad application prospect in the C- H bond activation reaction. Through the synergistic effect with metals, oxides and organic ligands, acetic acid-based catalytic systems have made significant progress in reaction activity, selectivity and stability. Future research still needs to focus on revealing its mechanism of action, optimizing catalytic performance and promoting its industrial application. It can be predicted that with the deepening of research, acetic acid will play a more important role in the C- H bond activation reaction, and inject new impetus into the green chemical industry and sustainable development.