Zirconium triflate grafted on SBA-15 as a highly efficient solid acid catalyst for ring opening of epoxides by amines and alcohols

Metal(Al,Ti,Zr)triflate grafted mesoporous SBA‐15(AlTf/S,TiTf/S,ZrTf/S)samples were synthesizedas inexpensive solid acid materials by a simple one‐pot‐two‐step synthesis methodology.These materials were characterized by X‐ray diffraction,N2‐sorption,thermogravimetric analysis,Fourier transform infrared spectroscopy(FT‐IR),in‐situ pyridine FT‐IR spectroscopy,and elementalanalysis.ZrTf/S was found to be a highly efficient and reusable solid acid catalyst for ring opening ofepoxides with amines and alcohols and producedβ‐amino alcohols andβ‐alkoxy alcohols respectivelyunder ambient reaction conditions.The ZrTf/S catalyst showed the highest activity,whichwas attributed to its high acidity compared with that of the Ti and Al containing samples.

Al(HSO_4)_3/silica gel as a novel catalytic system for the ring opening of epoxides with thiocyanate anion under solvent-free conditions

For the first time,metal hydrogen sulfates and phosphates/silica gel have been studied as efficient and powerful solid acid catalysts in the ring opening of epoxides with thiocyanate anion.The most significant result was obtained by Al(HSO4)3/SiO2which afforded the corresponding β-hydroxy thiocyanates under mild reaction conditions and in very short reaction times.The cheapness, availability of the catalyst,ease of procedure and work-up make this method attractive for the organic synthesis.

STUDY ON THE INTRAMOLECULAR CVCLIZATION THROUGH OPENING OF EPOXIDE II RING CLOSURE OF N-METHYL-N-BENZOYLMETHYLENE-β-PHENYL-α,β-EPOXYPROPIONAMIDE IN PROTIC SOLVENT

When the title compound was treated in protic solvent with alkali catalyses,γ-lacatam was almost the sole product.The ratio of ketone 1 to ketone 2 depended upon the reaction condition.

2-Amino homopropargyl alcohols from the highly regioselective Ag_2CO_3-catalyzed nucleophilic openings of alkynyl epoxides by amines

The nucleophilic ring opening reaction of propargyl epoxides by amines based on a silver catalyst is presented, The reaction takes place under mild conditions and features a high regioselectivity to provide an effective method for the synthesis of 2-amino homopropargyl alcohols in moderate to high yields,

Shi Epoxidation:A Great Shortcut to Complex Compounds

Shi epoxidation provides an extremely powerful tool to access optically active epoxides,which undoubtedly belongs to one of the earliest and most successful organocatalytic systems.Several generations of chiral ketones have been developed to realize the asymmetric epoxidation of each type of unfunctionalized alkenes,including trans-,trisubstituted olefins,cis-olefins,terminal olefins,and tetrasubstituted olefins.Due to its reliability and high regio-and enantioselectivity,Shi epoxidation has been widely applied in the synthesis of complex natural products and biologically active molecules.

A VERSATILE AND REGIOSELECTIVE SYNTHESIS OF VICINAL AZIDOALCOHOLS USING CROSS-LINKED POLY(4-VINYLPYRIDINE) SUPPORTED AZIDE ION UNDER SOLVENT-FREE CONDITIONS

A new polymeric reagent, cross-linked poly（4-vinylpyridine） supported azide ion, [P4-VP]N3, was introduced as polymeric reagents for efficient and regioselective conversion of epoxides to azidohydrins in the presence of cross-linked poly（4-vinylpyridine） supported sulfuric acid, [P4-VP]H2SO4, as a solid proton source and as catalyst under solvent-free conditions. The advantages of this polymeric reagent over some of those reported in the literature are easy work-up procedure and regeneration of the reagent.