In this novel acid-base jointly promoted CuAAC, the combination of CuI/DIPEA/HOAc was developed as a highly efficient catalytic system. The functions of DIPEA and HOAc have been assigned, and HOAc was recognized to accelerate the conversions of the C-Cu bond-containing intermediates and buffer the basicity of DIPEA. As a result, all drawbacks occurring in the popular catalytic system CuI/NR(3) were overcome easily.

An extremely convenient method for deprotection of acetals and ketals catalyzed by molecular iodine (10 mol %) in acetone is reported. The protocol achieved the deprotection of acyclic or cyclic O,O-acetals and O,O-ketals in excellent yields within a few minutes under neutral conditions. The double bond, hydroxyl group, and acetate group remained unchanged, and the highly acid-sensitive furyl, tert-butyl ethers, and ketone-oxime stayed intact under these conditions.

In this article, the structurally well-defined dinuclear complex copper(I) acetate was studied in detail and was developed as a highly practical and efficient catalyst for the copper(I)-catalyzed azide-alkyne cycloaddition. The "bare" phenylethynylcopper(I) (i.e., with no exogeneous ligands) was isolated as an intermediate, which can be converted into an active catalytic species by treatment with acetic acid (in situ produced in the reaction) to efficiently catalyze the azide-alkyne cycloaddition under mild conditions.

A general and efficient procedure for the preparation of phenols was developed by copper-catalyzed oxidative hydroxylation of arylboronic acids at room temperature in water.

In lower nitrile solvents, the N-arylation of azoles with aryl halides was achieved efficiently in the presence of copper powder without any additional ligands. Thus, the first nitrile type of monodentate ligand-mediated, "ligand-free-like" coppercatalyzed N-arylation procedure was established.