A highly practical synthesis of 1-naphthols was developed via Cp*Co(iii)-catalyzed C–H activation and cyclization between sulfoxonium ylides and alkynes.

A highly monoselective synthesis of ferrocenyl alkynes was achieved via Cu-promoted ferrocene C­(sp2)–H bond activations. The reaction employs an 8-aminoquinoline group as the directing group and terminal alkynes as the alkyne source. It was found the alkynylation products actually complex with the in situ generated Cu­(I) ions to give robust and stable alkyne π-copper complexes. In addition, these alkyne π-copper complexes could be freed of the copper ions to give various ferrocenyl alkynes in almost quantitative yields. The test results also showed that the alkyne π-copper complexes could be reformed from the free alkynes upon treating them with Cu­(I) salts.

A novel and efficient synthesis of sulfones was developed via a silver-promoted decarboxylative sulfonylation reaction between aromatic carboxylic acids and sodium sulfinates for the first time. The approach features operational simplicity and good functional group compatibility and uses readily available starting materials. Furthermore, mechanistic studies reveal that the decarboxylative sulfonylation reaction is likely to proceed via a radical mechanism.

An efficient protocol for the synthesis of internal aryl alkynes was achieved via Cu-catalyzed decarboxylative cross-coupling reactions, and to the best of our knowledge, this is the first example of a Cu-catalyzed decarboxylative alkynylation of benzoic acids with terminal alkynes. This approach utilizes simple Cu salt as catalyst and O, an abundant, clean, and green material, as the oxidant. The reaction tolerates various functional groups, and a variety of internal aryl alkynes were synthesized in 46-83% yields.

No abstract