Synthesis and Crystal Structure Determination of [H2-cryptand 222](Br3)2: A Unique Tribromide Catalyst for the Catalytic Chemoselective N-Boc Protection of Amines

Comparison of the effectiveness of two piperazine based nano-catalysts in the synthesis of benzoxazoles and benzimidazoles and use of the powerful one in the N-Boc protection of amines

In this work, a comparison between the catalytic activity of two piperazine based ionic liquids immobilized on ZnO NPs and SiO2 NPs is presented in the synthesis of benzoxazoles and benzimidazoles. These reactions are performed under solvent free conditions during appropriate reaction times with high yields. The catalyst obtained from ZnO-NPs (PINZS), as the more efficient one, is used for the efficient promotion of the N-Boc protection of amines. High chemoselectivity, no by-products, facile separation of the catalyst, short reaction times and no need for volatile organic solvents are the best features of the proposed methods.

Applications of Selectfluor for the oxidation of Sulfides, urazoles and alcohols under the solvent-free conditions

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Selectfluor acts as a safe and efficient reagent for the oxidation of urazoles, alcohols and also sulfides via releasing the electrophile F under the solvent-free conditions. In room temperature, this reagent cannot oxidize the substrates alone and requires KBr as the catalyst. In the proposed mechanism, Selectfluor converts the Br- to the Br-F and the lone-pair electron of substrates attack to Br-F to perform the oxidation reaction. This procedure offers some advantages; for example short reaction time, simple work-up, good yield and matching with some green chemistry approaches.

Synthesis of ynones at room temperature catalyzed by copper chloride cryptand complex under solvent free conditions

An air-stable highly efficient reusable CuCl2-cryptand-[2.2.Benzo] catalyst is reported first time for coupling reaction of terminal alkynes with different acyl chlorides in the presence of triethylamine acting both as base and solvent at room temperature to give the corresponding ynones. Easy-going, short reaction time, cost-effective, palladium-, phosphorus- and solvent-free, high yield and recyclability up to 5th times make this method green procedure for ynones' synthesis with wide substrate variety.