Many primary,secondary,tertiary alcohols,and phenolic hydroxyl groups were effectively converted to their corresponding trimethylsilyl ethers using hexamethyldisilazane in the presence of catalytic amounts of tribromo...Many primary,secondary,tertiary alcohols,and phenolic hydroxyl groups were effectively converted to their corresponding trimethylsilyl ethers using hexamethyldisilazane in the presence of catalytic amounts of tribromoisocyanuric acid and DABCO-bromine under mild conditions at room temperature with short reaction times in good to excellent yields.Excellent chemoselective silylation of hydroxyl groups in the presence of other functional groups were also observed.展开更多
{[K.18-Crown-6]Br3}n,a unique tribromide-type catalyst,was utilized for the N-boc protection of amines and trimethylsilylation(TMS)and tetrahydropyranylation(THP)of alcohols.The method is general for the preparation o...{[K.18-Crown-6]Br3}n,a unique tribromide-type catalyst,was utilized for the N-boc protection of amines and trimethylsilylation(TMS)and tetrahydropyranylation(THP)of alcohols.The method is general for the preparation of N-boc derivatives of aliphatic(acyclic and cyclic)and aromatic,and primary and secondary amines and also various TMS-ethers and THP-ethers.The simple separation of the catalyst from the product is one of the many advantages of this method.展开更多
Melamine and poly vinylpyrrolidone （PVP） reacted with neat sulfuric acid readily to form two new organic solid acids namely melamine-（H2SO4）3 and PVP-（H2SO4）n. These solid acids were used for the first nitration...Melamine and poly vinylpyrrolidone （PVP） reacted with neat sulfuric acid readily to form two new organic solid acids namely melamine-（H2SO4）3 and PVP-（H2SO4）n. These solid acids were used for the first nitration of bisphenol A as well as other phenols in the presence of NHaNO3. Mono- and di-nitro bisphenol A have been characterized with IR and ^1H NMR techniques.展开更多
基金Supported by Bu-Ali Sina University Research Council.
文摘Many primary,secondary,tertiary alcohols,and phenolic hydroxyl groups were effectively converted to their corresponding trimethylsilyl ethers using hexamethyldisilazane in the presence of catalytic amounts of tribromoisocyanuric acid and DABCO-bromine under mild conditions at room temperature with short reaction times in good to excellent yields.Excellent chemoselective silylation of hydroxyl groups in the presence of other functional groups were also observed.
基金support for this work from the research affairs of Hamedan University of Medical Sciences,Hamedan,I.R.Iranpartial support of this work by the Research Affairs Office of Bu-Ali Sina UniversityCenter of Excellence in Development of Chemical Method(CEDCM)Hamedan,I.R.Iran
文摘{[K.18-Crown-6]Br3}n,a unique tribromide-type catalyst,was utilized for the N-boc protection of amines and trimethylsilylation(TMS)and tetrahydropyranylation(THP)of alcohols.The method is general for the preparation of N-boc derivatives of aliphatic(acyclic and cyclic)and aromatic,and primary and secondary amines and also various TMS-ethers and THP-ethers.The simple separation of the catalyst from the product is one of the many advantages of this method.
基金financial support for this work from the research affairs of Hamedan University of Medical Sciences, Hamedan,I.R.Iran and partial support of this work by the Research Affairs Office of Bu-Ali Sina University(Grant number 32-1716 entitled development of chemical methods,reagent and molecules.) Hamedan,I.R.Iran
文摘Melamine and poly vinylpyrrolidone （PVP） reacted with neat sulfuric acid readily to form two new organic solid acids namely melamine-（H2SO4）3 and PVP-（H2SO4）n. These solid acids were used for the first nitration of bisphenol A as well as other phenols in the presence of NHaNO3. Mono- and di-nitro bisphenol A have been characterized with IR and ^1H NMR techniques.
