Poly(4-vinylpyridine) catalyzed chemoselective O-TMS protection of alcohols and phenols and N-Boc protection of amines (original) (raw)
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Communication 1,3-Dichloro-5,5-dimethylhydantoin (DCH) and Trichloromelamine (TCM) as Efficient Catalysts for the Chemoselective Trimethylsilylation of Hydroxyl Group with 1,1,1,3,3,3-Hexamethyldisilazane (HMDS) under Mild Conditions A highly convenient method for the trimethylsilylation of alcohols and phenols via treatment by hexamethyldisilazane in the presence of 1,3-dichloro-5,5-dimethylhydantoin (DCH) and/or trichloromel-amine (TCM) as a catalyst has been developed. A wide variety of hydroxyl groups were selectively protected in CH 2 Cl 2 /CH 3 CN under mild conditions.
Journal of The Iranian Chemical Society, 2012
N-sulfonic acid poly(4-vinylpyridinium) chloride is easily prepared by the reaction of poly(4-vinylpyridine) with neat chlorosulfonic acid. This reagent can be used as an efficient catalyst for the N-Boc protection of amines at room temperature and neat conditions. This new method consistently has the advantages of excellent yields and short reaction times. Further, the catalyst can be reused and recovered for several times. Keywords N-sulfonic acid poly(4-vinylpyridinium) chloride Á Solvent-free conditions Á N-Boc protection Á Poly(4-vinylpyridine) Á Heterogeneous catalysis
Journal of Molecular Catalysis A: Chemical, 2011
Poly(4-vinylpyridine) perchlorate, is a supported, recyclable, eco-benign catalyst for the reaction acetylation of structurally diverse alcohols, phenols and amines at room temperature under solvent-free conditions. The catalyst was studied by FT-IR, X-ray diffraction, Scanning Electron Microscope and Thermo-gravimetric Analyses. All the products were extensively characterized by 1 H NMR, FT-IR, GC-MS and melting point analyses. The catalyst can be recovered and reused without loss of activity. The workup of the reaction consists of a simple filtration, followed by concentration of the crude product and purification. It is important to point out that a large-scale reaction is possible using a same amount of catalyst.
Journal of Molecular Catalysis A-chemical, 2012
Poly(4-vinylpyridine) perchlorate, is a supported, recyclable, eco-benign catalyst for the reaction acetylation of structurally diverse alcohols, phenols and amines at room temperature under solvent-free conditions. The catalyst was studied by FT-IR, X-ray diffraction, Scanning Electron Microscope and Thermo-gravimetric Analyses. All the products were extensively characterized by 1 H NMR, FT-IR, GC-MS and melting point analyses. The catalyst can be recovered and reused without loss of activity. The workup of the reaction consists of a simple filtration, followed by concentration of the crude product and purification. It is important to point out that a large-scale reaction is possible using a same amount of catalyst.
Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry, 2012
The protection of alcohols with hexamethyldisilazane (HMDS) in the presence of P 2 O 5 /SiO 2 at very mild and ambient condition with short reaction times is accomplished in excellent yields. P 2 O 5 /SiO 2 catalyst is an efficient solid acid and heterogeneous catalyst for this transformation and easily recovered and reused for several times without significant decrease in its activity. Selectivity studies showed competitive reaction of primary alcohols over secondary alcohols and phenols.
CuI-NPs catalyzed mechanochemical-assisted N-Boc protection of organic amines
Indian Journal of Chemistry -Section B
A simple, solvent-free, faster and mechanochemical approach for the N-tert-butoxycarbonylation of amines catalyzed by copper iodide nanoparticles as a recyclable catalyst is described. The advantages of this method are simplicity, shorter reaction time (5-15 min), a cost-effective catalyst, and excellent product isolation (82-92%). N-Boc protection of various structurally diverse aliphatic, aromatic, and heterocyclic amines have been carried out with (Boc) 2 O with 10 mol% catalyst under pestle mortar grinding under solvent-free conditions. The catalyst possesses distinct advantages, ease of handling as well as removal, cleaner reactions, high activity, and environmentally benign. The final product has been characterised by various spectroscopic techniques.