Cu-catalyzed aerobic oxidative three-component coupling of a terminal alkyne, secondary amine, and sulfonamide enables efficient synthesis of amidines. The use of Cu(OTf)2 (5 mol %) produces amidines selectively without Glaser-Hay alkyne homocoupling products. Preliminary studies suggest that the reaction pathway involves initial oxidative coupling of the terminal alkyne with the secondary amin...

The use of the bulky hydrotris(3-mesitylpyrazolyl)borate anionic ligand has allowed the synthesis of stable Tp(Ms)Cu(alkyne) complexes (alkyne = 1-hexyne, 1, phenylacetylene, 2, and ethyl propiolate, 3). The spectroscopic and structural features of these compounds and their relative reactivity have been examined, indicating the existence of a low π back-bonding from the copper(I) centre to the ...

As a new model of chemical assay-guided natural product isolation, an effective chemodosimetric assay system was devised. Our chemical assay system features a fluorogenic chemodosimeter immobilized on a solid support, which offers advantages in identifying the desired compounds in complex natural product mixtures. To isolate only compounds with the target functional groups, the click chemistry ...

As a new model of chemical assay-guided natural product isolation, an effective chemodosimetric assay system was devised. Our chemical assay system features a fluorogenic chemodosimeter immobilized on a solid support, which offers advantages in identifying the desired compounds in complex natural product mixtures. To isolate only compounds with the target functional groups, the click chemistry ...

The copper-catalyzed azide alkyne cycloaddition is employed to modify phosphatidylcholine precursors with sn-2 acyl chains containing terminal alkyne or azide groups. Although the reactions are conducted as biphasic dispersions, the yields are essentially quantitative. Bolaamphiphiles are formed by simply clicking together two phosphatidylcholine alkyne precursors to a central bisazide scaffold...

A novel strategy for alkyne-alkyne cross-coupling has been developed under the palladium catalysis. In this reaction, ene-yne-ketones are employed as carbene precursors, which couple with terminal alkynes through the metal carbene migratory insertion process. Furan-substituted enynes are obtained in good yields and in a stereoselective manner.

A modular synthetic method for bis- and tris-1,2,3-triazoles that include a benzotriazole structure was developed on the basis of sequential azide-aryne and azide-alkyne cycloadditions. The key to success was efficient halogen-metal exchange reaction-mediated generation of aryne from ortho-iodoaryl triflates bearing a base-sensitive terminal alkyne moiety, which was achieved using trimethylsily...

A simple and convenient method for the preparation of ultra-small palladium nanoparticles (Pd-NPs) by a modified digestive ripening method is described. These nanoparticles catalyse the hydrogenation of the terminal alkyne groups to alkanes selectively, and show no effect on other labile protecting and internal alkyne or internal/external alkene groups present in the molecule.

o-Alkynylarenenitriles when heated with Pd(OAc)2/H2O/(±)-CSA in DMSO undergo simultaneous alkyne oxidation and nitrile hydration to give 3-aryl-3-hydroxy-2,3-dihydroazanaphthoquinones. Upon treatment with (±)-CSA, these compounds form 3-arylazanaphthoquinones in situ, which add to electron-rich aromatics and terminal alkene/alkyne to afford 3,3-disubstituted-2,3-dihydroazanaphthoquinones.