A visible-light-induced photocatalyst-free three-component radical cascade bicyclization has been achieved to obtain diverse difluoroamidosulfonylated dihydrobenzofurans in moderate to good yields. This protocol avoids potential toxicity and the tedious removal procedure for photocatalysts and also features mild reaction conditions and a good functional group tolerance. Moreover, mechanistic investigations reveal the formation of a charge-transfer complex and the involvement of an intramolecular 1,5-hydrogen atom transfer process in this transformation.
View Article and Find Full Text PDFThe direct synthesis of isocoumarin skeletons has been realized through the Rh(III)-catalyzed [3 + 3] annulation of sulfoxonium ylides with iodonium carbenes. The synthetic protocol was constructed efficiently with broad functional group tolerance and mild reaction conditions. This reaction can be formally viewed as the result of C-H activation, carbene insertion and nucleophilic addition processes.
View Article and Find Full Text PDFA novel Rh(III)-catalyzed annulation of phthalazinones or pyridazinones with various allenes was developed, leading to the formation of indazole derivatives bearing a quaternary carbon in moderate to good yields. The targeted products were synthesized sequential C-H activation and olefin insertion, followed by β-hydride elimination and intramolecular cyclization. The synthetic protocol proceeded efficiently with broad functional group tolerance, high atom efficiency and high -selectivity.
View Article and Find Full Text PDFWe investigated a novel Cu-catalyzed annulation of 2,3-allenoic acids with diphenylphosphine oxide, leading to the formation of 4-phosphate butenolides in up to 88% yield. The formation of the C-P bond provides new avenues for the functionalization of different furan-2(5)-ones, with favorable features such as suitable functional group tolerance and mild synthesis conditions.
View Article and Find Full Text PDFBackground: Chloranthus serratus (Chloranthaceae) has been used to treat bruises, rheumatoid and bone pain. However, the anti-inflammatory mechanisms of C. serratus in vitro have not been fully elucidated.
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