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Described is a copper-catalyzed cascade reaction method for the conversion of 3,4-dihydropyrimidine-2(1 H )-thiones to arylthiopyrimidines, likely proceeded via C–S cross-coupling and oxidative dehydrogenation under aerobic conditions. The reaction method proceeded efficiently with a wide range of the dihydropyrimidinethione substrates and aryl iodides as coupling partners.

For the presented approach no further additives like oxidants, acids, or bases are required.

Common intermediates to biogenic precursors of arteminolides are synthesized via a key silicon-tethered intramolecular [5 + 2]oxidopyrylium cycloaddition reaction.

Functionality preferences of metathesis Ru carbenes to various alkenes and alkynes with electronic and steric diversity were determined by using time-dependent fluorescence quenching. The functionality preferences depend not only on the properties of multiple bonds but also on the ligands on Ru. There was a good correlation between functionality preference and the metathesis reaction outcome. The correlation between functionality preference and exo/endo product ratio offers a solution to resolve the mechanistic issue related with alkene- vs alkyne-initiated pathway in ring-closing enyne metathesis. The correlation indicates the preference is likely to dictate the reaction pathway and eventually the outcome of the reaction. The Ru catalyst favoring alkyne over alkene provides more endo product, indicating that the reaction mainly initiates at the alkyne. By changing the substitution pattern, the preference can be reversed to give an exclusive exo product.

involving metathesis reactions for the preparation of diene fragments (III) and (V) as the key steps

Compound (III), which has the common ring skeleton of the B- and B′-rings of arteminolides, is synthesized in eight steps starting from 1,3-propanediol via an unprecedented intramolecular [5 + 2] oxidopyrylium cycloaddition reaction with vinylsilyl ether tether as key step.

We describe a rapid and efficient method for selective deprotection of methoxymethyl (MOM) ethers using ZnBr2 and n-PrSH, which completely removed MOM from diverse MOM ethers of primary, secondary, and tertiary alcohols or phenol derivatives. The deprotection takes less than ten minutes with both high yield and selectivity in the presence of other protecting groups. In addition, the rapid deprotection of MOM ethers of tertiary hydroxyls in high yield with no epimerization allows MOM to be a suitable protecting group for tertiary alcohols.

The oxidopyrylium cycloaddition reaction of allenes was investigated. Contrary to other cycloaddition reactions, electron deficient allenes were not reactive at all and electron rich allenes were slightly more reactive than neutral allenes. The intermolecular cycloaddition reaction occurred at the terminal position regardless of substitution patterns. For the intramolecular reaction only the perhydroazulene structure was obtained over other possible products.

The first example of tripeptide inhibitors of farnesyltransferase with sub-micromolar inhibition activity was developed based on the fact that CVFM is not a substrate for farnesyltransferase.