Treatment of (E)-1-(methoxymethylene)-1,2,3,4-tetrahydronaphthalene with styryl diazoacetates in the presence of catalytic amounts of the dirhodium complex Rh2(S-DOSP)4 provides a highly enantioenriched hexacyclic product with 10 new stereogenic centers. The transformation proceeds by a cascade sequence starting with a double cyclopropanation of a benzene ring, followed by a Cope rearrangement ...

A novel NHC-catalyzed three-component domino strategy to access high functionalized cis-ε-ketoesters with excellent yields (up to 98%) and high stereoselectivities (up to 20:1) is documented. The title domino reactions are atom economical and work on a broad range of substrates. The relative stereochemistry could be explained by a cascade crossed-benzoin/oxy-Cope rearrangement/esterification pr...

The hemisynthesis of the naturally occurring bioactive flavonoid glycoside icariin (1) has been accomplished in eleven steps with 7% overall yield from kaempferol. The 4'-OH methylation of kaempferol, the 8-prenylation of 3-O-methoxymethyl-4'-O-methyl-5-O-prenyl-7-O-benzylkaempferol (8) via para-Claisen-Cope rearrangement catalyzed by Eu(fod)3 in the presence of NaHCO3, and the glycosylation of...

A strained aza-dibenzocyclooctyne was prepared via a high-yielding synthetic route. Copper-free, strain-promoted click reaction with azides showed excellent kinetics, and a functionalised aza-cyclooctyne was applied in fast and efficient PEGylation of enzymes.

8-Azainosine (8-aza-HR) is of interest because of its activity against experimental tumors. Metabolic studies in cell cultures were performed with 8-aza-HR and with the structurally related nucleoside, 8-azaadenosine (9-beta-D-ribofuranosyl-8-azaadenine) (8-aza-AR), which has a lower degree of antitumor activity than does 8-aza-HR. In H. Ep. 2 cells and in Ca755 cells, both 14C-labeled nucleosi...

The development of new catalytic asymmetric reactions can lead to exciting new strategies for organic synthesis. This article describes the synthetic utility of the combined C-H activation/Cope rearrangement, achieved by dirhodium tetraprolinate-catalyzed reaction of vinyldiazoacetates with compounds containing allylic C-H bonds. The transformation is highly diastereoselective and enantioselect...

The application of 2-arylcyclopropylmethanols as substitutes to homoallyl aryl alcohols and their reactions with aliphatic aldehydes in the presence of SnCl4 in CH2Cl2 leads to an efficient Prins cyclization to generate cis-2,6-disubstituted tetrahydropyrans in high yields. The reaction is free from 2-oxonia-Cope rearrangement. This protocol was used to synthesize (±)-centrolobine in an overall...

The year 2022 has been one of hybrid events all over the world, as we emerge from effects and aftereffects COVID-19. With repercussions still lingering, there are many aspects that need to be addressed before announcing any event. We geared up attend IEEE Antennas Propagation Society (AP-S) International Symposium on Propagation/U.S. National Committee–International Union Radio Science Meeting ...