1523-06-4Relevant articles and documents
Diazepinium perchlorate: a neutral catalyst for mild, solvent-free acetylation of carbohydrates and other substances
Giri, Santosh Kumar,Gour, Rajesh,Kartha, K. P. Ravindranathan
, p. 13653 - 13667 (2017/03/11)
Diazepinium perchlorate, an essentially neutral organic salt possessing excellent stability, has been found to be well suited for the acetylation of free as well as partially protected sugars, phenols, thiophenols, thiols and other alcohols as well as amines. The diazepinium perchlorate-catalyzed acetylation is mild, organic and solvent-free and leaves acid sensitive protecting groups such as TBDMS/TBDPS/Tr ethers and isopropylidene/benzylidene acetals present on a substrate unaffected. Regioselective hydroxyl protection in partially protected carbohydrate derivatives/polyhydroxylic compounds was possible and was proved to be a convenient time-saving alternative to the conventional synthesis of such compounds. Easy preparation of the catalyst, mild reaction conditions and an environmentally benign protocol are some of the notable features of this reaction. The results obtained on the acetylation of phenols and thiophenols could be rationalized through their local nucleophilicity index obtained from DFT calculations.
Magnetically separable γ-Fe2O3 nanoparticles: An efficient catalyst for acylation of alcohols, phenols, and amines using sonication energy under solvent free condition
Bhosale, Manohar A.,Ummineni, Divya,Sasaki, Takehiko,Nishio-Hamane, Daisuke,Bhanage, Bhalchandra M.
, p. 8 - 17 (2015/04/27)
This paper reports a facile synthesis of magnetically separable iron oxide (γ-Fe2O3) nanoparticles using thermolysis method. The structural and morphological study of the synthesized γ-Fe2O3 nanoparticles was carried out using X-ray diffraction (XRD), field emission gun-scanning electron microscopy (FEG-SEM), energy dispersive X-ray spectrum (EDS), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS) techniques. The electron microscopy reveals that the γ-Fe2O3 nanoparticles have spherical morphology with a particle size in the range of 40-100 nm. The XPS study confirmed the Fe is in +3 oxidation state. The synthesized γ-Fe2O3 nanoparticles have been used as an efficient heterogeneous catalyst for the organic transformation between phenols, alcohols, and amines with acetic anhydride under sonication using mild reaction conditions. Various electrons withdrawing and electrons donating substrates show an excellent yield of desired products with the advantage of magnetic separation and reusability of γ-Fe2O3 nanocatalyst.
