The copper catalyzed 1,3-dipolar cycloaddition of 4-butoxyphenylazide with 2-, 3- or 4-ethynylpyridine furnishes 1,4-diaryltriazoles, which display turn-on fluorescence upon addition of metal cations.

The [3,5,5,7] tetracyclic skeleton of echinopines has been stereoselectively accessed through a gold(I)-catalyzed alkoxycyclization of cyclopropyl-tethered 1,6-enynes. The key bicyclo[4.2.1]nonane core of the enyne precursors was readily assembled by means of a Co-catalyzed [6 + 2] cycloaddition. Furthermore, the attempted alkoxycyclization of 1,5-enyne substrates revealed an uncovered cyclopro...

A Rh-catalyzed 1,3-acyloxy migration of propargyl ester followed by intramolecular [4+2] cycloaddition of vinylallene and unactivated alkyne was developed. This tandem reaction provides access to bicyclic compounds containing a highly functionalized isotoluene or cyclohexenone structural motif, while only aromatic compounds were observed in related transition metal-catalyzed cycloadditions.

A synthetic methodology is reported that functionalizes C60 and C70 fullerenes with dihydroazepine rings by a cascade reaction encompassing rhodium-catalyzed cycloisomerization of 1,5-bisallenes [4+2] cycloaddition. This transition metal-catalyzed provides versatile step-economical approach to the synthesis 6,7-membered polyheterocyclic fullerene adducts. Electrochemical characterization produc...

Pyritides belong to the ribosomally synthesized and post-translationally modified peptide class of natural products that were recently genome-predicted are structurally defined by unique pyridine-containing macrocycles. Inspired their biosynthesis, proceeding through modification cycloaddition form heterocyclic core, we report chemical synthesis pyritide A2 involving pyridine ring from an amino...

A highly diastereo- and chemoselective intramolecular nickel-catalyzed cycloaddition of alkene- and alkyne-tethered alkynylidenecyclopropanes is reported. The method constitutes the first fully intramolecular [3 + 2 + 2] alkylidenecyclopropropane cycloaddition occurring via a proximal cleavage of the cyclopropane and makes it possible to build relevant 6,7,5-tricyclic frameworks in a single-pot...

Regioselective ring expansion of alkynyl cyclopropanes to highly substituted cyclobutenes was developed. The reaction involves a copper-catalyzed cycloaddition of an alkyne with an arylsulfonyl azide and a silver-catalyzed carbene formation followed by ring expansion of a cyclopropyl carbene intermediate.