2209-25-8Relevant academic research and scientific papers
Synthesis and characterization of N-glucosylated dithiadiazepine derivatives through carbon-sulfur bond formation
Chavan, Snehal A.,Ulhe, Avinash G.,Berad, Baliram N.
, p. 269 - 272 (2015/10/28)
New 4,7-bis(arylamino)-2-tetra-O-acetyl-β-d-glucopyranosylimino-1,3,5,6-dithiadiazepines were synthesized via reaction of N-tetra-O-acetyl-β-d-glucopyranosyl isocyanodichloride with 1,6-diaryl-2,5-dithio-bis-ureas without using any catalyst. Thus, the syn
Desulfurization strategy in the construction of azoles possessing additional nitrogen, oxygen or sulfur using a copper(I) catalyst
Guin, Srimanta,Rout, Saroj Kumar,Gogoi, Anupal,Nandi, Shyamapada,Ghara, Krishna Kanta,Patel, Bhisma K.
, p. 2757 - 2770 (2013/01/15)
A tandem and convergent approach to various N-, O-, or S-containing azoles has been developed by exploiting the thiophilic property of copper( I) iodide used in a catalytic quantity. The present protocol gives access to amino-substituted tetrazoles, triazoles, oxadiazoles and thiadiazoles via oxidative desulfurization of their respective precursors followed by inter- or intramolecular attack of suitable nucleophiles. For aminotetrazoles and triazoles an excellent regioselectivity has been achieved through proper tuning of the pKa values of the parent amines attached to unsymmetrical thioureas. The method represents an autocatalytic process in which copper( I) iodide gets converted to copper(II) sulfide which in turn transforms to active copper(II) oxide that effectively carries forward the catalytic cycle. The fate of the copper catalyst has also been studied using scanning electron microscopic (SEM) and energy-dispersive X-ray spectroscopic (EDS) analyses which give an insight into the mechanism for this catalytic process.
Tandem regioselective synthesis of tetrazoles and related heterocycles using iodine
Yella, Ramesh,Khatun, Nilufa,Rout, Saroj Kumar,Patel, Bhisma K.
supporting information; experimental part, p. 3235 - 3245 (2011/06/20)
A one-pot, tandem process has been developed for the synthesis of a library of tetrazoles from aryl isothiocyanates. Condensation of aryl isothiocyanates with ammonia, and aryl amines (R-NH2) provided mono, 1,3-disubstituted symmetrical and unsymmetrical thioureas, which on desulfurization with molecular iodine (I2) led to formation of the corresponding heterocumulene (cyanamides or carbodiimides). The in situ generated heterocumulene on subsequent treatment with sodium azide at room temperature gave corresponding tetrazoles. The product regioselectivity for unsymmetrical 1,3-disubstituted thioureas was found to be correlated with the basicities (pKa's) of the parent amines attached to the thiourea. Aryl-sec-alkyl unsymmetrical thioureas gave thioamido guanidino products rather than the 5-aminotetrazoles produced by HgCl2 mediation of the reaction. Bis-thioureas derived from aryl isothiocyanates and hydrazine gave thiadiazoles exclusively.
NMR studies of saccharide hydrazones, thiosemicarbazones and azines: Model compounds for immobilisation studies
Tweeddale, Helen J.,Redmond, John W.
, p. 27 - 38 (2007/10/03)
To evaluate possible chemical strategies for the solid-phase immobilization of sugars, studies on the formation and stability of hydrazones, thiosemicarbazones and azines of D-glucose and 2-acetamido-2-deoxy-D-glucose, and the subsequent release of sugars, were carried out. Hydrazone formation was observed to occur under milder conditions than previously reported, thereby minimising the accompanying N-deacetylation which occurs with N-acetamido sugars. The cyclic β-pyranosyl structures of the saccharide hydrazones, thiosemicarbazones and azines were the preferred isomers in aqueous solution.
