The laccase-catalyzed reaction between unsubstituted catechol and 2-thioxopyrimidin-4(1H)-ones using aerial O 2 as the oxidant delivers novel pyrimidobenzothiazoles with high yields in an aqueous solvent system under mild reaction conditions. With 4-substituted catechols, catechol thioethers are formed exclusively. The synthetic protocols developed provide a sustainable approach for these compound classes. In addition, the cytotoxicity of the products against HepG2 cell line is reported. Most compounds exhibit antiproliferative activities with IC 50 values at the micromolar level. A structureactivity relationship study will facilitate the further development of these compounds as cytotoxic agents.

The copper‐catalyzed double intramolecular Ullmann coupling of syn‐1,2‐bis(2‐bromoaryl)ethane‐1,2‐diols with catalytic amounts of CuII oxinate as the copper source, K3PO4 as a base, and KI as a reductant in aqueous acetonitrile selectively delivers 4b,9b‐dihydrobenzofuro[3,2‐b]benzofurans in diastereomerically and enantiomerically pure form and yields of up to 90 %. The substrates can be obtained in both diastereomerically and enantiomerically pure form by catalytic dihydroxylation of the corresponding (E)‐stilbenes.

1'-O-Chlorogenoylchlorogenic acid and 1'-O-chlorogenoylneochlorogenic acid, a new type of quinic acid esters, have been isolated, in addition to six known quinic acid esters, rutin, and a mixture of saponins, from the methanol extract of Cussonia barteri Seemann (Araliaceae) leaves collected in Cameroon. Structure determination was achieved by NMR, mass, IR, and UV spectroscopy. All compounds were tested for inhibitory activity on 5-lipoxygenase and cyclooxygenase-1, for antimicrobial activity against Bacillus subtilis, Pseudomonas fluorescens, and Cladosporium cucumerinum, and for haemolytic activity.

A transition-metal-free route for the synthesis of several N-fused heterocycles, including thiazolo[3,2-a]benzimidazoles and imidazo[2,1-b]thiazoles, is reported. The reaction between propargyl tosylates and 2-mercaptobenzimidazoles under basic conditions results in 3-substituted thiazolo[3,2-a]benzimidazoles, in yields up to 92% in a single synthesis step. With 2-mercaptoimidazoles as the substrate, the corresponding imidazo[2,1-b]thiazoles were exclusively obtained. The transformation is considered to proceed as an intermolecular S-propargylation that is followed by 5-exo-dig ring closure and double-bond isomerization.

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