TBN as Organic Redox Cocatalyst for Oxidative Tiffeneau-Demjanov-Type Rearrangement Using O2 as Sole Oxidant.

The Tiffeneau-Demjanov-type rearrangement is a ring-expansion reaction involving the cationic rearrangement of cyclic alcohols. The carbocation intermediates can be generated in situ via various means, including Wacker oxidation. In near recent reports on the reinvestiagtions by Wahl et al. (Sietmann, J.; Tenberge, M.; Wahl, J. M. Wacker Oxidation of Methylenecyclobutanes: Scope and Selectivity in an Unusual Setting. Angew. Chem., Int. Ed. 2023, 62, e202215381) and Zhu et al. (Feng, Q.; Wang, Q.; Zhu, J.-P. Oxidative Rearrangement of 1,1-Disubstituted Alkenes to Ketones. Science 2023, 379, 1363-1368), stoichiometric oxidants were involved. In this work, we report the Tiffeneau-Demjanov-type rearrangement can be smoothly promoted by the Pd-TBN cocatalyzed aerobic Wacker oxidation using molecular oxygen as the sole oxidant. tert-Butanol is essential for achieving high yields. Since the first report by Grigg et al. in 1977 (Boontanonda, P.; Grigg, R. J. Palladium (II)-Catalysed Ring Expansion of Methylenecyclobutanes and Related Systems. J. Chem. Soc. Chem. Commun. 1977, 17, 583-584), the five-decade journey of Pd-catalyzed Tiffeneau-Demjanov-type rearrangement returns to the aerobic again.

Piper longum L. ameliorates gout through the MAPK/PI3K-AKT pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Gout, a painful joint disease with a prevalence ranging from 0.86% to 2.2% in China over the past decade. Traditional medicine has long utilized the medicinal and edible Piper longum L. (PL) fruit spikes for treating gout and other joint conditions like rheumatoid arthritis. However, the exact mechanisms behind its effectiveness remain unclear. AIM OF THE STUDY: This study aimed to investigate the potential of alcoholic extracts from PL fruit spikes as a safe and effective treatment for gout. We used a combined network pharmacology and experimental validation approach to evaluate the mechanisms behind the anti-gout properties of PL. MATERIALS AND METHODS: UPLC-Q/TOF-MS analysis determined the major components of PL. Subsequently, network pharmacology analysis predicted potential molecular targets and related signaling pathways for the anti-gout activity of PL. Molecular docking simulations further explored the interactions between PL compounds and proteins and characterized the properties of potential bioactive secondary metabolites. Mouse models of air pouch inflammation and hyperuricemia were further established, and the anti-gout mechanism of PL was confirmed by examining the expression of proteins related to the MAPK and PI3K-AKT pathways in the tissue. RESULTS: Our analysis revealed 220 bioactive secondary metabolites within PL extracts. Network pharmacology and molecular docking results indicated that these metabolites primarily combat gout by modulating the PI3K-AKT and MAPK signaling pathways. In vivo experiments have also proven that PL at a dose of 100 mg/kg can optimally reduce acute inflammation of gout and kidney damage caused by high uric acid. The anti-gout mechanism involves the PI3K-AKT/MAPK signaling pathway and its downstream NF-κB pathway. CONCLUSION: This study provides compelling evidence for PL's therapeutic potential in gout management by modulating key inflammatory pathways. The findings offer a strong foundation for future clinical exploration of PL as a gout treatment option.

Stereospecific Palladium-Catalyzed Direct Glycosylation of Oximes: Access to N-O-Linked Glycosides.

A highly efficient, palladium-catalyzed glycosylation between 3,4-O-carbonate glycals and acid-labile oximes is disclosed. This approach features broad substrate scope, high functional group tolerance, and easy scalability, delivering glycosyl oximes in excellent yields with exclusive ß-selectivity and retention of Z/E geometries. The power of this method is demonstrated by a set of site-selective transformations of glycosylation products and late-stage glycodiversification of bioactive molecules. Overall, our strategy provides an efficient toolkit for facile access to valuable N-O-linked glycosides.

Potential anti-gout properties of Wuwei Shexiang pills based on network pharmacology and pharmacological verification.

ETHNOPHARMACOLOGICAL RELEVANCE: Wuwei Shexiang Pills (WWSX), a classic Tibetan medicine, consists of Chebulae Fructus (removed pit), Aucklandiae Radix, Moschus, Aconiti Fiavi Radix, and Acori Calami Rhizoma. It is used clinically in China to treat joint pain, swelling and other symptoms, and has the function of dispelling wind and relieving pain. However, to date, the mechanism of how it works against gout is still unclear. AIMS OF THE STUDY: Using network pharmacology, molecular docking and pharmacological verification to explore the potential anti-gout properties of WWSX. MATERIALS AND METHODS: With the use of UPLC-Q/TOF-MS, the main components of WWSX were obtained and screened for potential anti-inflammatory components by network pharmacology and molecular docking. The anti-inflammatory activity of the components screened from WWSX was also tested by in vitro assays. The anti-gout mechanism of WWSX was predicted by network pharmacology, and the pharmacological validation experiments using gouty arthritis model and mouse air pouch model were used to explore the multifaceted mechanism of WWSX to modify gout. RESULT: Thirty-eight active ingredients were obtained from the UPLC-Q/TOF-MS detection. The network pharmacology and molecular docking analysis showed that 104 co-targets were participated in the treatment of gout, and the main signaling pathways involved were NOD-like receptor pathway, NF-κB pathway and MAPK pathway. Pharmacological evaluation showed that WWSX could significantly improve gout in gouty arthritis models and mouse air pouch models by modulating the above pathways. CONCLUSION: This work has predicted and validated the anti-inflammatory material basis and predicted the anti-gout mechanism of WWSX which was verified by network pharmacology, molecular docking and in vitro cellular studies. The results reveal the mechanism of WWSX in the treatment of gout and provide a theoretical basis for its clinical application.

Direct Synthesis of ß-Amino Aldehydes from Linear Allylic Esters Using O2 as the Sole Oxidant.

A tandem isomerization-anti-Markovnikov oxidation of linear allylic imidic esters is developed using bis(benzonitrile)palladium chloride as the catalyst and O2 as the sole oxidant, regiospecifically giving ß-amino aldehydes as the product. tert-Butyl nitrite works as a simple, and the only, redox cocatalyst. tBuOH proves to be a crucial solvent for achieving excellent yield and specificity toward anti-Markovnikov aldehyde products.

Iron-Catalyzed α,ß-Dehydrogenation of Carbonyl Compounds.

An iron-catalyzed α,ß-dehydrogenation of carbonyl compounds was developed. A broad spectrum of carbonyls or analogues, such as aldehyde, ketone, lactone, lactam, amine, and alcohol, could be converted to their α,ß-unsaturated counterparts in a simple one-step reaction with high yields.