A novel synthesis of 1,2,4-oxadiazoles and isoxazoles

Zora, Metin
A novel synthesis of 1,2,4-oxadiazoles and isoxazoles is described by utilizing the reactions between amidoximes and alpha,beta-alkynic aldehydes and/or ketones. Conjugate addition products, obtained from amidoximes and alpha,beta-alkynic aldehydes and/or ketones, afford 1,2,4-oxadiazoles and isoxazoles when treated with bases and acids, respectively. 1,2,4-Oxadiazoles can also be synthesized directly from amidoximes and alpha,beta-alkynic aldehydes in a one-pot manner under basic conditions. The reactions are general for a variety of starting compounds and tolerate the presence of aryl, heteroaryl and alkyl groups.


A novel one-pot, three-component reaction for the synthesis of isocoumarin-condensed pyrazoles
OZCAN, Sevil; Dengiz, Çağatay; DELIOMEROGLU, Murat K.; ŞAHİN, Ertan; BALCI, METİN (Elsevier BV, 2011-03-30)
The one-pot, three-component reaction of substituted homophthalic anhydrides with hydrazine in DMF as solvent and reactant, at reflux temperature, afforded isochromeno[3,4-c]pyrazole-5(2H)-one derivatives in high yields. The mechanism and roles of the substrates were investigated and it was found that cyclic hydrazides were formed as intermediates.
Synthesis of 1,2,3,5-tetrasubstituted pyrrole derivatives from 2-(2-bromoallyl)-1,3-dicarbonyl compounds
Demir, Ayhan Sıtkı; Akhmedov, IM; Sesenoglu, O (Elsevier BV, 2002-12-02)
2-(2-Bromoallyl)-1,3-dicarbonyl compounds are converted into beta-enamino, beta-hydrazino esters and ketones, followed by base-promoted cyclization, leading to the formation of the corresponding 1,2,3,5-tetrasubstituted pyrroles. 1,2,4- and 1,2,3,4-Substituted pyrroles are also isolated as minor products. Starting from the 2-(2-bromoallyl)-cyclohexane-1,3-dione the corresponding tetrahydro indolone is prepared in good yield.
Synthesis of chiral acetoxy lactones via the Baeyer-Villiger oxidation of cyclic aromatic acetoxy ketones
Demir, Ayhan Sıtkı; Aybey, Asuman (Elsevier BV, 2008-12-01)
The alpha-acetoxylation of indanones and tetralones by using Mn(OAc)(3) followed by the enzyme catalyzed kinetic resolution of acetoxy ketones furnished both of the enantiomers of alpha-acetoxy ketones in good chemical and optical yields. The Baeyer-Villiger oxidation of alpha-acetoxy ketones with m-CPBA, CF(3)SO(3)H, and CH(2)O(2), at rt gives the corresponding lactones without racemization. The acetoxy ketone moiety migrates selectively in order to form lactones. The mild hydrolysis of lactones affords ph...
Synthesis and properties of a novel redox driven chemiluminescent material built on a terthienyl system
Atilgan, Nurdan; Algi, Fatih; Önal, Ahmet Muhtar; CİHANER, ATİLLA (Elsevier BV, 2009-07-18)
A novel redox driven chemiluminescent material built on a terthienyl system, namely 5,7-di-ethylenedioxythiophen-2-yl-2,3-dihydro-thieno[3,4-d]pyridazine-1,4-dione (ETE-Lum), which is soluble in both organic media and basic aqueous solution was synthesized and characterized. Furthermore, its polymer, PETE-Lum, which is one of the most rare examples of chemiluminescent polymeric materials bearing a pyridazine unit, was obtained successfully by electrochemical means. Both of the materials give chemiluminescen...
One-pot synthesis of iodine-substituted 1,4-oxazepines
Zora, Metin; KELGÖKMEN, YILMAZ (Elsevier BV, 2018-02-28)
A facile one-pot method for the synthesis of iodine-substituted 1,4-oxazepines is reported. When reacted with ZnCl2 and I-2 in DCM at 40 degrees C, N-propargylic beta-enaminones, prepared by the conjugate addition of propargylamine to alpha,beta-alkynic ketones, underwent 7-exo-dig cyclization by zinc chloride and concomitant reaction with molecular iodine to afford 2-(iodomethylene)-2,3-dihydro-1,4-oxazepines in good to high yields. This cyclization was found to occur with broad scope of substrates and hig...
Citation Formats
A. KIVRAK and M. Zora, “A novel synthesis of 1,2,4-oxadiazoles and isoxazoles,” TETRAHEDRON, pp. 817–831, 2014, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/42653.