A sequential [3 + 2]/[2 + 1] annulation domino reaction of crotonate-derived sulfur ylides and Morita–Baylis–Hillman carbonates of isatins for the construction of oxospiro­[bicyclo[3.1.0]­hexane-6,3′-indolin] scaffolds in moderate to good yields with almost 1:1 diastereoselectivity has been developed. Mild reaction conditions and readily accessible starting materials as well as excellent functional group compatibility render this transformation a powerful tool for the synthesis of spirocyclopropyloxindoles. A gram-scale synthetic procedure was also successfully carried out and a plausible reaction mechanism could be proposed.

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An unparalleled [4 + 2]-annulation of prop-2-ynylsulfonium salts with isatoic anhydrides was developed, affording a series of 4-quinolones with a alkylthio group in medium to good yields under mild conditions. In this reaction type, the prop-2ynylsulfonium salt serves as a C2 synthon and sulfide does not act as a leaving group, providing facile access to organosulfur compounds. The resulting quinolone products could be further transformed to a diverse range of synthetically useful compounds.

The electrocatalytic CO 2 reduction reaction (CO 2 RR) to generate syngas (a mixture of CO and H 2 ) is considered as one of the most effective routes to peak C and C neutrality. However, it is challenging to regulate the CO/H 2 ratio by adjusting the activity of CO 2 RR. To address this problem, transition metals were designed to be encapsulated in C shells and loaded onto Ndoped C (NG) substrate catalysts for CO 2 RR generation of syngas. Comparative electrochemical tests revealed that Fe and Ni nanoparticles supported on N-doped C matrix (denoted as Fe/NG and Ni/NG) produce CO/H 2 in a wide range of relative ratios, thereby limiting their application in real industrial production. In contrast, FeÀ Ni alloy nanoparticle supported on NG matrix (denoted as Fe 2 Ni/NG, where the subscript represents the molar ratio of the Fe source to Ni source) catalysts containing both Fe and Ni with a molar ratio of 2 : 1 exhibit high syngas evolution (1.2-2.9), suitable for typical downstream thermochemical reactions. The results provide a useful case for nonprecious metals to retain CO 2 RR, maintaining high activity while flexibly regulating the CO/H 2 ratio.

Die Metaboliten (II) des Probenecids (I) werden synthetisiert und ihre UV‐ Spektren, pKa‐Werte und Verteilungskoeffizienten bestimmt.