Cascade hydroarylation/Diels-Alder cycloaddition of alkynylindoles with electron-deficient alkynes and alkenes.

Herein, a novel cascade gold(I)-catalyzed hydroarylation of alkynylindoles and subsequent Diels-Alder cycloaddition with electron-deficient alkynes and alkenes is described. A variety of azepino-fused hydrocarbazoles and carbazoles were obtained in moderate to excellent yields. Key features of this methodology are low catalyst loadings, high regioselectivity, broad functional group tolerances, access to important heterocycles, and 100% atom economy.

Metabolic-associated fatty liver disease and risk of esophagogastric cancer: a systematic review and meta-analysis.

INTRODUCTION: Metabolic-associated fatty liver disease (MAFLD) has been found to be strongly linked to several diseases. Although previous studies have explored the association between MAFLD and extrahepatic cancers, research on the relationship between MAFLD and gastric carcinoma (GC) and esophageal carcinoma (EC) is relatively scarce and requires updating. Therefore, the objective of this study is to conduct a comprehensive investigation into the association between MAFLD and GC or EC. MATERIAL AND METHODS: We conducted a comprehensive search for relevant studies published up to 5 August 2022, using the PubMed, Embase and Web of Science databases. To estimate the risk ratio (RR) and the 95% confidence interval (CI), we employed a random-effects model. We also conducted subgroup analyses based on study characteristics. The protocol for this systematic review is registered in the Prospero database under the registration number CRD42022351574. RESULTS: Our analysis included eight eligible studies, comprising a total of 8 629 525 participants. We found that the pooled RR values for the risk of GC in patients with MAFLD were 1.49 (95%CI: 1.17-1.91), whereas the pooled RR values for the risk of EC in patients with MAFLD were 1.76 (95%CI: 1.34-2.32). CONCLUSIONS: Based on our meta-analysis, we conclude that there is a significant association between the presence of MAFLD and the development of GC and EC.

Access to Azepino-Annulated Benzo[c]carbazoles Enabled by Gold-Catalyzed Hydroarylation of Alkynylindoles and Subsequent Oxidative Cyclization.

Herein, we report a facile and efficient synthetic method to construct azepino[1,2-a]indoles through a novel gold(I)-catalyzed intramolecular hydroarylation of alkynylindoles. A wide range of functional groups can be well tolerated in this transformation, and the corresponding highly functionalized azepino[1,2-a]indole skeletons were obtained in moderate to excellent yields. Subsequent oxidation of the products gave the interesting and valuable polycyclic carbazoles, which were widely used as the key building blocks in materials science.

Syntheses and structures of copper complexes of 3-(6-(1H-pyrazol-1-yl)pyridin-2-yl)pyrazol-1-ide and their excellent performance in the syntheses of nitriles and aldehydes.

Reactions of a pincer ligand 2-(1H-pyrazol-1-yl)-6-(1H-pyrazol-3-yl)pyridine (pzpypzH) with Cu(NO3)2, Cu(ClO4)2, CuSO4, CuCl2 or CuI produced three dinuclear Cu(ii) complexes [{Cu(NO3)}(µ-pzpypz)]2 (1), [{Cu(ClO4)}(µ-pzpypz)]2 (2), [Cu2(µ-SO4)(µ-pzpypz)2]·2MeOH (3·2MeOH), one mononuclear Cu(ii) complex [CuCl2(pzpypzH)] (4) and one trinuclear Cu(i)/Cu(ii) complex [(ICu)(µ-I)2Cu2(µ-pzpypz)2] (5), respectively. Treatment of 4 with two equiv. of AgNO3 in DMF also gave rise to 1. Complexes 1-5 were characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. Complex 1 or 2 has a dimeric structure in which two {Cu(X)} (X = NO3, ClO4) fragments are interconnected by two µ-pzpypz(-) ligands. 3 also adopts a dimeric structure in which two Cu(ii) centers are interconnected by a pair of µ-pzpypz(-) ligands and one µ-SO4(2-) ion. The Cu(ii) center in 4 is five-coordinated by three N atoms of the pzpypzH ligand and two Cl atoms. In 5, two Cu(ii) centers are bridged by two µ-pzpypz(-) ligands and one CuI3(2-) unit, forming a unique trinuclear structure. Complexes 1-5 displayed high catalytic activity toward the ammoxidation of alcohols to nitriles and the aerobic oxidation of alcohols to aldehydes in H2O. The nitrile or aldehyde products could be readily separated from the catalytic system by extraction and the residual aqueous solution containing 1 retained good activity for several cycles.