Two types of highly efficient and operationally simple reactions of ynamides under metal-free conditions are developed, including hydroacyloxylation and hydration, which afforded highly functionalized α-acyloxyenamides and pharmaceutically important N-acylsulfonamides in good to excellent yields.

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The 1,5‐diazabicyclo[4.3.0]non‐5‐ene (DBN)‐catalyzed regioselective acylation of carbohydrates and diols in ethyl acetate has been developed. The hydroxyl groups can be selectively acylated by the corresponding anhydride in EtOAc in the presence of a catalytic amount (as low as 0.1 equiv.) of DBN at room temperature to 40 °C. This method avoids metal catalysts and toxic solvents, which makes it comparatively green and mild, and it uses less organic base compared with other selective acylation methods. Mechanism studies indicated that DBN could catalyze the selective acylation of hydroxyl moieties through a dual H‐bonding interaction.

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A novel and efficient palladium-catalyzed one-pot synthesis of imidazoloindolines from 2-alkynyl arylazides under mild reaction conditions has been described. This method features wide substrate applicability, resistance of water and air...