A practical innovative method for highly selective oxidation of alkenes and alkanes using Fe (III) and Mn (III) porphyrins supported onto multi‐wall carbon nanotubes as reusable heterogeneous catalysts

Heterogeneous Iron-Based Catalysts for Organic Transformation Reactions: A Brief Overview

Iron (Fe) is considered to be one of the most significant elements due to its wide applications. Recent years have witnessed a burgeoning interest in Fe catalysis as a sustainable and cost-effective alternative to noble metal catalysis in organic synthesis. The abundance and low toxicity of Fe, coupled with its competitive reactivity and selectivity, underscore its appeal for sustainable synthesis. A lot of catalytic reactions have been performed using heterogeneous catalysts of Fe oxide hybridized with support systems like aluminosilicates, clays, carbonized materials, metal oxides or polymeric matrices. This review provides a comprehensive overview of the latest advancements in Fe-catalyzed organic transformation reactions. Highlighted areas include cross-coupling reactions, C-H activation, asymmetric catalysis, and cascade processes, showcasing the versatility of Fe across a spectrum of synthetic methodologies. Emphasis is placed on mechanistic insights, elucidating the underlying principles governing iron-catalyzed reactions. Challenges and opportunities in the field are discussed, providing a roadmap for future research endeavors. Overall, this review illuminates the transformative potential of Fe catalysis in driving innovation and sustainability in organic chemistry, with implications for drug discovery, materials science, and beyond.

SERS Tracking Oxidative Stress on a Metalloporphyrin Framework by Vitamin C

Accurate control of charge transfer is crucial to investigate the catalytic reaction mechanism of the biological oxidation process that biomedicine participates in. Herein, we have established an assembly model of metalloporphyrin framework (MPF) nanosheets as the active centers of biological enzymes. The introduction of Vitamin C (VC) into the MPF system can precisely modulate its content of charges. The surface-enhanced Raman scattering activity and peroxidase-like catalytic performance are enhanced simultaneously for the first time by manipulating the optimal molar ratio of an MPF to VC and the reaction sequence with target model molecules. We have confirmed that the formation of the intermediate of Fe(2+)-OOH species is specifically enhanced after VC modulation, which indicates that VC can regulate the oxidative stress of the active center of biological enzymes. This discovery not only accurately resolves the mechanism of VC-selective anticancer therapy but also has important significance for the precise treatment of VC synergistic targeting medicines.

Selective Photocatalyst for styrene epoxidation with atmospheric O2 using covalent organic frameworks

Fe@POG-OH was synthetized and used to photo-catalyze styrene epoxidation with high selectivity and high conversion at room temperature. O2˙− plays crucial roles in the effective and selective oxidation of styrene to styrene oxide.

Full use of factors promoting catalytic performance of chitosan supported manganese porphyrin

In order to make full use of the impact of internal and external factors on the performance of title catalyst for ethyl benzene oxidation, the key internal influencing factors on the catalytic performance were modulated by coordinating and grafting manganese porphyrin to mesoporous and macroporous chitosan, and the important external factors (i.e. oxidation reaction conditions) were optimized using Response Surface Methodology. Under the Response Surface Methodology optimized oxidation reaction conditions (176.56 °C, 0.59 MPa, and 0.25 mg amount of manganese porphyrin), the catalyst could be used at least five times. The ethyl benzene conversion, catalyst turnover numbers, and yields reached up to 51.2%, 4.37 × 106 and 36.4% in average, respectively. Compared with the other optimized oxidation reaction conditions, the corresponding values increased 17%, 26% and 53%. Relative to the manganese porphyrin, the catalytic performance and efficiency of the immobilized catalyst had notably increased.