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A tandem palladium-catalyzed Sonogashira coupling, propargyl-allenyl isomerization, and [2+2] cycloaddition sequence between electrondeficient haloarenes and 1,8-diynylic ethers is developed. The reaction shows good functional tolerance and proceeds under mild conditions to provide a new profile of benzooxepane-fused cyclobutene derivatives in moderate to high yields with high selectivity. The reaction mechanism is validated both by experimental studies and DFT calculations. [ABSTRACT FROM AUTHOR]

Mesoporous titania microspheres composed of nanosheets with exposed active facets were prepared by hydrothermal synthesis in the presence of hexafluorosilicic acid. They exhibited superior catalytic activity in the solvent-free synthesis of azoxybenzene by oxidation of aniline and could be used for 7 cycles with slight loss of activity. [ABSTRACT FROM AUTHOR]

Polysubstituted 5-functionalized 2-pyrone derivatives were synthesized via the K2CO3-catalyzed reaction of 1,2-allenyl esters and a-substituted ketones with electron-withdrawing groups through a tandem nucleophilic addition/lactonization process. [ABSTRACT FROM AUTHOR]