- Halogen bonding two-point recognition with terphenyl derivatives
-
Two-point recognition involving neutral terphenyl-based halogen bond donors (halogen-based Lewis acids) was investigated. Oxadiazole and pyridazole derivatives were identified by DFT as suitable binding partners, even though gas-phase binding was weak. X-
- Stoesser,Rojas,Bulfield,Hidalgo,Pasán,Ruiz-Pérez,Jiménez,Huber
-
-
Read Online
- A novel 1-D coordination polymer constructed from disilver-1,3,4-oxadiazole nodes and perchlorato bridges
-
The reaction of silver perchlorate with 2-phenyl-5-(p-tolyl)-1,3,4-oxadiazole (L) affords a 1-D coordination polymer, [Ag3L4(ClO4)3] (1). Two silver ions are bridged by two L ligands, through the nitrogen atoms of the oxadiazole ring, resulting in binuclear units. The coordination polymer is constructed from binuclear nodes, {Ag2L2}, connected by perchlorato bridges. The investigation of the optical properties of compound 1 indicates a slight change in the emission profile compared to the organic ligand, showing blue luminescence upon excitation at λ?=?300?nm.
- Anghel, Catalin,Matache, Mihaela,Paraschivescu, Codruta C.,Madalan, Augustin M.,Andruh, Marius
-
-
Read Online
- The preparation, characterization and catalytic activity of Ni NPs supported on porous alginate-g-poly(p-styrene sulfonamide-co-acrylamide)
-
Herein, we report the synthesis of nickel nanoparticles under mild conditions using porous alginate-g-poly(p-styrene sulfonamide-co-acrylamide) as a protecting/stabilizing agent and sodium borohydride as a reducing agent. The porous cross-linked polymeric support was preparedviacombining the use of sol-gel, nanocasting, and crosslinking techniques, in which thep-styrene sulfonamide monomer (PSSA) andN,N′-methylene-bis (acrylamide) (MBA) cross-linker underwent copolymerization on the surface of sodium alginate in the presence of a SiO2nanoparticle (NP) template (Alg-PSSA-co-ACA). The prepared catalyst (Alg-PSSA-co-ACA@Ni) showed high catalytic activity for the one-step synthesis of 1,3,4-oxadiazoles from the reaction of hydrazides and aryl iodides through isocyanide insertion/cyclization.
- Alavinia, Sedigheh,Ghorbani-Vaghei, Ramin
-
p. 29728 - 29740
(2021/10/06)
-
- Experimental and Theoretical Studies on the Mechanism of DDQ-Mediated Oxidative Cyclization of N-Aroylhydrazones
-
The controversial single-electron-transfer process, frequently proposed in many 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)-mediated reactions, was investigated experimentally and theoretically using the oxidative cyclization of aroylhydrazone with DDQ. DDQ-mediated oxadiazole formation involves several processes, including cyclization to form an oxadiazole ring and N-H bond cleavage, either by proton, hydride, or hydrogen atom transfer. The detailed mechanistic study using the M06-2X density functional theory, and the 6-31+G(d,p) basis set, suggests that the pathways involving radical ion pair (RIP) intermediates, which resulted from single-electron transfer (SET), were found to be energetically nearly identical to the pathway without the SET. The substituent-dependent reactivity of oxadiazole formation was consistent with the free energy profiles of both pathways, with or without the SET. This result indicates that in addition to the electron-transfer pathway, the nucleophilic addition/elimination pathway for DDQ should be considered as a possible mechanism of the oxidative transformation reaction using DDQ.
- Baek, Jihye,Je, Eun-Kyung,Kim, Jina,Qi, Ai,Ahn, Kwang-Hyun,Kim, Yongho
-
p. 9727 - 9736
(2020/10/02)
-
- UV-Induced 1,3,4-Oxadiazole Formation from 5-Substituted Tetrazoles and Carboxylic Acids in Flow
-
A range of 1,3,4-oxadiazoles have been synthesized using a UV-B activated flow approach starting from carboxylic acids and 5-substituted tetrazoles. The application of UV light represents an attractive alternative to the traditional thermolytic approach and has demonstrated comparable efficiency and versatility, with a diverse substrate scope, including the incorporation of highly substituted amino acids.
- Green, Luke,Livingstone, Keith,Bertrand, Sophie,Peace, Simon,Jamieson, Craig
-
supporting information
p. 14866 - 14870
(2020/11/11)
-
- Electrochemical Synthesis of 2,5-Disubstituted 1,3,4-Oxadiazoles from α-Keto Acids and Acylhydrazines Under Mild Conditions
-
1,3,4-Oxadiazoles are a kind of useful heterocycles which can be frequently found in materials and bioactive molecules. In this study, intermolecular electrochemical cyclization between α-keto acids and acylhydrazines has been developed for the synthesis of 2,5-disubstituted 1,3,4-oxadiazoles with the yield up to 91 %. This transformation can be run under mild reaction conditions in the absence of external oxidant, base and transition metal catalyst. Both symmetrical and unsymmetrical 2,5-disubstituted 1,3,4-oxadiazoles could be prepared according to the careful choice of the substrate combination. Gram scale synthesis also illustrates the potential application of this protocol in large preparation.
- Lu, Fangling,Gong, Fengping,Li, Liangsen,Zhang, Kan,Li, Zhen,Zhang, Xinwei,Yin, Ying,Wang, Ying,Gao, Ziwei,Zhang, Heng,Lei, Aiwen
-
supporting information
p. 3257 - 3260
(2020/05/25)
-
- Reusable colorimetric and fluorescent chemosensors based on 1,8-naphthalimide derivatives for fluoride ion detection
-
Two 1, 8-naphthalimide derivatives, 2-(2-ethylhexyl)-6-(2-(4-(5-phenyl-1,3,4-oxadiazol-2-yl)benzylidene)hydrazinyl)-1H-benzo[de]isoquinoline-1,3(2H)-dione (named as NAOZ) and 2-(2-ethylhexyl)-6-(2-(4-(5-phenyl-1,3,4-thiadiazol-2-yl)benzylidene)hydrazinyl)
- Ding, Liang,Gao, Junkuo,Zhang, Feng,Zhang, Liang
-
-
- Palladium-catalyzed direct C2-arylation of azoles with aromatic triazenes
-
A highly efficient palladium-catalyzed arylation of azoles at the C2-position using 1-aryltriazenes as aryl reagents was developed. Azoles including oxazoles, thiazoles, imidazoles, 1,3,4-oxadiazoles, and oxazolines could react with 1-aryltriazenes smoothly to generate the corresponding products in good to excellent yields, and various substitution patterns were tolerated toward the reaction.
- Liu, Can,Wang, Zhiming,Wang, Lei,Li, Pinhua,Zhang, Yicheng
-
p. 9209 - 9216
(2019/11/05)
-
- Harnessing Autoxidation of Aldehydes: In Situ Iodoarene Catalyzed Synthesis of Substituted 1,3,4-Oxadiazole, in the Presence of Molecular Oxygen
-
Isobutyraldehyde underwent auto-oxidation in the presence of molecular oxygen to generate an acyloxy radical under a "metal-free" environment. They were subsequently exploited in situ to afford hypervalent iodines with p-anisolyl iodide which generated substituted 1,3,4-oxadiazoles in moderate to excellent yields from N′-arylidene acetohydrazides. The reaction strategy tolerated diverse substitution on the hydrazide substrates. Control experiments and literature precedence supported the formation of an in situ iodosylarene complex that facilitates the formation of products.
- Chauhan, Jyoti,Ravva, Mahesh K,Sen, Subhabrata
-
p. 6562 - 6565
(2019/09/04)
-
- Mixed N-heterocycles/N-heterocyclic carbene palladium(II) allyl complexes as precatalysts for direct arylation of azoles with aryl bromides
-
A series of mixed N-heterocycles/N-heterocyclic carbene palladium(II) allyl complexes with general formula [(NHC)Pd(η3-allyl)]2(μ2-N-heterocycles)(BF4)2 were prepared in one pot based on anion metathesis of (NHC)Pd(η3-allyl)Cl complexes and then ligand replacement with N-heterocycles [N-heterocycles = pyrazine (pyz), 4,4′-bipyridine (bpy) and trans-4,4′-bipyridylethylene (bpe)]. The solid-state structures shown dinuclear structures with two palladium(II) centers holding together by bridged N-heterocycles. Initially investigation of the obtained complexes as precatalysts for direct C[sbnd]H bond arylation of azoles with aryl bromides was carried out.
- Yang, Jin
-
p. 2182 - 2187
(2019/02/24)
-
- Photocatalyzed facile synthesis of 2,5-diaryl 1,3,4-oxadiazoles with polyaniline-?g-C3N4-TiO2 composite under visible light
-
PANI (polyaniline)-g-C3N4-TiO2 composite was prepared and found to be efficient for the synthesis of 2,5-diaryl 1,3,4-oxadiazoles under visible light. This reaction involved decarboxylation and cyclization from α-keto acids with acylhydrazines, and a broad scope of substrates were tolerated to provide the desired products in moderate to good yields. Control experiments indicated that a radical pathway was involved in the present photocatalytic reaction and a synergistic effect may exist in the ternary composite. Moreover, this semiconductor photocatalyst could be readily recovered and showed good reusability with only slight decrease in the catalytic activity after six consecutive runs.
- Wang, Liang,Wang, Yaoyao,Chen, Qun,He, Mingyang
-
supporting information
p. 1489 - 1492
(2018/03/13)
-
- Synthesis of 2,5-disubstituted 1,3,4-oxadiazoles by visible-light-mediated decarboxylation–cyclization of hydrazides and diketones
-
A visible-light-induced synthesis of 2,5-disubstituted 1,3,4-oxadiazoles from simple diketones and hydrazides with the assistant of the photocatalyst eosin Y catalyzed decarboxylation and cyclization under mild conditions has been discovered. The reaction tolerates a wide range of functional groups and gives a variety of valuable 1,3,4-oxadiazoles in moderate to good yields. Finally, a plausible reaction mechanism was proposed.
- Diao, Pinhui,Ge, Yanqin,zhang, Wenpei,Xu, Chen,Zhang, Nannan,Guo, Cheng
-
supporting information
p. 767 - 770
(2018/02/07)
-
- Ligand-free Cu(ii)-mediated aerobic oxidations of aldehyde hydrazones leading to N,N′-diacylhydrazines and 1,3,4-oxadiazoles
-
A Cu(ii)-mediated synthesis of N,N′-diacylhydrazines and 1,3,4-oxadiazoles from aldehyde hydrazones has been developed. This is the first time that the synthesis of N,N′-diacylhydrazines and 1,3,4-oxadiazoles using N,N-dimethylamides as the acylation reagent and O2 in air as the oxidation reagent is reported. These reactions offered several advantages including simple workups, ligand-free inexpensive metal salts as mediators, high yields, and wide scope of substrates.
- Liu, Lei,Feng, Suliu
-
supporting information
p. 2585 - 2592
(2017/04/03)
-
- 2,5-Diaryloxadiazoles and their precursors as novel inhibitors of cathepsins B, H and L
-
High levels of cathepsins indicated in various pathological conditions like arthritis, cancer progressions, and atherosclerosis explains the need to explore potential inhibitors of these proteases which can be of great therapeutic significance. We, in the present work, report the synthesis of some 2,5-diaryloxadiazoles from N-subsitutedbenzylidenebenzohydrazides. The synthesized compounds were screened for their inhibitory potential on cathepsins B, H and L. Structure Activity Relationship studies show that 2,5-diaryloxadiazoles were less inhibitory than their precursors. 1i and 2k have been found to be most inhibitory to cathepsins B and L. Their Ki values have been calculated as 11.38 × 10-8 M and 66.4 × 10-8 M for cathepsin B and 4.2 × 10-9 M and 47.31 × 10-9 M for cathepsin L, respectively. However, cathepsin H activity was maximally inhibited by compounds, 1e and 2c with Ki values of 4.4 × 10-7 M and 5.6 × 10-7 M, respectively. Enzyme kinetic studies suggest that these compounds are competitive inhibitors to the enzymes. The results have been compared with docking results obtained using iGemDock.
- Garg, Shweta,Raghav, Neera
-
-
- Oxidation of sp3C—H bonds in N-alkylhydrazides: Access to 2,5-disubstituted 1,3,4-oxadiazole derivatives
-
The oxidation of sp3C[sbnd]H bonds in N-alkylhydrazides was achieved en route to the efficient synthesis of a broad series of 1,3,4-oxadiazoles. Mechanistic studies have revealed that N-acylhydrazone is a key intermediate in this catalytic transformation.
- Zhang, Liang,Zhao, Xiaolong,Jing, Xiaobi,Zhang, Xuewen,Lü, Shiwei,Luo, Liangliang,Jia, Xiaodong
-
supporting information
p. 5669 - 5672
(2016/11/29)
-
- One-pot cyclization/decarboxylation of α-keto acids and acylhydrazines for the synthesis of 2,5-disubstituted 1,3,4-oxadiazoles under transition-metal-free conditions
-
A one-pot KI/TBHP-mediated oxidative cyclization of α-keto acids with acylhydrazines was developed. A series of functional 2,5-disubstituted 1,3,4-oxadiazoles were synthesized through a tandem keto amine condensation followed by oxidative cyclization and decarboxylation reactions. This procedure was achieved under transition-metal-free conditions and showed advantages including readily available materials, mild reaction conditions and good group tolerance.
- Gao, Peng,Wang, Juan,Bai, Zijing,Cheng, Hualei,Xiao, Jian,Lai, Mengnan,Yang, Desuo,Fan, Mingjin
-
supporting information
p. 4616 - 4619
(2016/09/23)
-
- Palladium-Catalyzed Aminocarbonylation Reaction to Access 1,3,4-Oxadiazoles using Chloroform as the Carbon Monoxide Source
-
A palladium-catalyzed aminocarbonylation reaction of aryl halides with chloroform and tetrazoles has been developed, where chloroform was employed as the carbon monoxide (CO) source in the presence of cesium hydroxide. The in situ generated N-acylated tetrazoles were unstable and easily decomposed to afford 2,5-disubstituted 1,3,4-oxadiazoles. A wide range of tetrazoles and aryl halides reacted smoothly under the optimized reaction conditions to give the corresponding products in moderate to good yields.
- Li, Zhengyi,Wang, Liang
-
p. 3469 - 3473
(2016/01/25)
-
- Palladium-catalyzed one-pot synthesis of diazoles via tert-butyl isocyanide insertion
-
An efficient one-pot palladium-catalyzed reaction for the synthesis of diazoles from readily available hydrazides and aryl halide via isocyanide insertion/cyclization sequence has been developed. This methodology efficiently constructs diazoles in good to excellent yields with the advantages of wide functional group tolerance and operational simplicity.
- Fan, Xiang-Yuan,Jiang, Xiao,Zhang, Ying,Chen, Zhen-Bang,Zhu, Yong-Ming
-
p. 10402 - 10408
(2015/10/28)
-
- Organocatalytic Oxidative Amidation of Aldehydes with Tetrazoles to Construct 2,5-Diaryl 1,3,4-Oxadiazoles
-
A practical and metal-free oxidative amidation of aldehydes with tetrazoles into 1,3,4-oxadiazoles has been developed by employing tetrabutylammonium iodide (TBAI) as catalyst and tert-butyl hydroperoxide (TBHP) as oxidant. A wide range of 2,5-disubstituted 1,3,4-oxadiazoles can be conveniently generated in moderate to good yields. Gram-scale reaction was also realized in this catalytic system..
- Cao, Jing,Wang, Liang
-
supporting information
p. 1239 - 1243
(2015/11/27)
-
- One-Pot Synthesis of 2,5-Diaryl 1,3,4-Oxadiazoles via Di-tert-butyl Peroxide Promoted N-Acylation of Aryl Tetrazoles with Aldehydes
-
A metal- and base-free protocol for one-pot synthesis of 2,5-diaryl 1,3,4-oxadiazoles via a radical-promoted cross-dehydrogenative coupling strategy was developed. This reaction involved the N-acylation of aryl tetrazoles with aryl aldehydes, followed by thermal rearrangement. A wide range of aryl tetrazoles and aryl aldehydes survived the reaction conditions to deliver the corresponding products in moderate to good yields. (Chemical Equation Presented).
- Wang, Liang,Cao, Jing,Chen, Qun,He, Mingyang
-
supporting information
p. 4743 - 4748
(2015/05/13)
-
- C-H arylation of azaheterocycles: A direct ligand-free and Cu-catalyzed approach using diaryliodonium salts
-
An efficient and high yielding Cu-catalyzed direct C-H arylation of azaheterocycles including oxadiazoles, thiadiazoles, benzoxazoles and benzothiazoles has been achieved by employing easily accessible diaryliodonium salts. the Partner Organisations 2014.
- Kumar, Dalip,Pilania, Meenakshi,Arun,Pooniya, Savita
-
supporting information
p. 6340 - 6344
(2014/08/18)
-
- Iodine-catalysed oxidative cyclisation of acylhydrazones to 2,5-substituted 1,3,4-oxadiazoles
-
An environmentally benign synthesis of 2,5-disubstituted 1,3,4-oxadiazoles has been developed starting from N-aroylhydrazones and N-acetylhydrazones at room or ambient temperature using a catalytic quantity of iodine in the presence of an aqueous hydrogen peroxide oxidant.
- Majji, Ganesh,Rout, Saroj Kumar,Guin, Srimanta,Gogoi, Anupal,Patel, Bhisma K.
-
p. 5357 - 5362
(2014/01/23)
-
- Efficient synthesis of 1,3,4-oxadiazoles promoted by NH4Cl
-
An efficient and inexpensive approach to the synthesis of 2-substituted and 2,5-disubstituted 1,3,4-oxadiazoles from arylhydrazides and orthoesters is reported using catalytic NH4Cl. The conditions are mild, and thus, compatible with a variety of functional groups. The optimized reaction is performed using 30 mol % of NH4Cl in 100% EtOH and is generally complete within 1 h for non-aromatic orthoesters and 2-10 h for aromatic orthoesters. The reaction permits both electron-releasing and electron-withdrawing groups on the arylhydrazide substrate. Most products are formed in high yields and require only minimal purification. Compared with earlier reports, the current reactions proceed in shorter time and require less of the orthoester.
- Gnanasekaran, Krishna Kumar,Nammalwar, Baskar,Murie, Maeghan,Bunce, Richard A.
-
supporting information
p. 6776 - 6778
(2015/01/09)
-
- Visible-light-promoted aerobic oxidative cyclization to access 1,3,4-oxadiazoles from aldehydes and acylhydrazides
-
A novel and practical access to symmetrical and unsymmetrical 2,5-disubstituted 1,3,4-oxadiazoles directly from aldehydes and acylhydrazides using visible light irradiation under an air atmosphere in the presence of eosin Y as an organophotoredox catalyst at rt is reported. This is the first example of oxidative cyclization of acylhydrazones employing air and visible light as inexpensive, readily available, non-toxic, and sustainable reagents.
- Yadav, Arvind K.,Yadav, Lal Dhar S.
-
supporting information
p. 2065 - 2069
(2014/04/03)
-
- Efficient oxidative cyclization of N -acylhydrazones for the synthesis of 2,5-disubstituted 1,3,4-oxadiazoles using t-BuOI under neutral conditions
-
An efficient procedure for the oxidative cyclization of N -acylhydrazones was developed utilizing tert-butyl hypoiodite (t-BuOI), which is generated in situ from t -BuOCl and NaI. A variety of 2,5-disubstituted 1,3,4-oxadiazoles were synthesized in high yields within short reaction time. The method is also suitable for cyclization of N -acylhydrazones derived from heterocyclic aldehydes and aliphatic aldehydes. Mild reaction conditions and simple workup operations make the procedure a good alternative for the synthesis of 2,5-disubstituted 1,3,4-oxadiazoles.
- Gao, Peng,Wei, Yunyang
-
p. 113 - 119
(2013/05/23)
-
- Efficient oxidative cyclisation of acid hydrazides to 2,5-disubstituted 1,3,4-oxadiazoles catalysed by Bu4NI with t-BuOOH as oxidant
-
Acid hydrazides or araldehyde N-acylhydrazones can be converted in good yields to, respectively, symmetrical or unsymmetrical, 2,5-disubstituted 1,3,4-oxadiazoles at 60 °C by a Bu4NI-catalysed procedure which requires the presence of a base and 2.5 equiv. of t-butyl hydroperoxide.
- Gao, Peng,Wei, Yunyang
-
p. 506 - 510
(2013/09/12)
-
- 2,4,6-Tris[(4-dichloroiodo)phenoxy)]-1,3,5-triazine as a new recyclable hypervalent iodine(III) reagent for chlorination and oxidation reactions
-
The synthesis of 2,4,6-tris[(4-dichloroiodo)phenoxy)]-1,3,5-triazine, as a new recyclable nonpolymeric analogue of (dichloroiodo)benzene, is achieved in two steps using 2,4,6-trichloro-1,3,5-triazine and 4-iodophenol. The application of 2,4,6-tris[(4-dichloroiodo)phenoxy)]-1,3,5-triazine for the chlorination reaction of various activated arenes, olefin, and 1,3-diketone is demonstrated. The reagent 2,4,6-tris[(4-dichloroiodo)phenoxy)]-1,3,5-triazine can be applied also for the oxidative synthesis of 1,3,4-oxadiazoles and 1,2,4-thiadiazoles under mild conditions in excellent yields. The recyclability of the 2,4,6-tris[(4-dichloroiodo)phenoxy)]-1,3,5-triazine was possible owing to the facile recovery and reuse of the coproduced 2,4,6-tris(4-iodophenoxy)-1,3,5- triazine from the reaction mixture due to its practical insolubility in methanol. Georg Thieme Verlag Stuttgart, New York.
- Thorat, Prerana B.,Bhong, Bhagyashree Y.,Karade, Nandkishor Y.
-
supporting information
p. 2061 - 2066
(2013/10/21)
-
- Electrosynthesis and screening of novel 1,3,4-oxadiazoles as potent and selective antifungal agents
-
The electrochemical oxidation of aldehyde-N-aroylhydrazone has been studied in the presence of NaClO4 as supporting electrolyte in MeOH solution using cyclic voltammetry and controlled potential electrolysis. The results indicate that intramolecular cyclization of aldehyde-N-aroylhydrazone has been successfully performed at a platinum electrode in an undivided cell with good yields of the corresponding 1,3,4-oxadiazoles at ambient conditions. The reaction products were characterized by spectroscopic methods and a mechanism was deduced from voltammetry studies. The antifungal activity of the synthesized compounds was evaluated on Fusarium oxysporum, Alternaria solani, Candida albicans and Aspergillus niger. The results revealed that all the synthesized compounds have significant antifungal activity against the tested fungi. Among the synthesized derivatives 7b, 7d, 7g, 7h, 7i, 7j and 7r were found to be the most effective antifungal compounds. The Royal Society of Chemistry 2013.
- Singh, Sushma,Sharma, Laxmi Kant,Saraswat, Apoorv,Siddiqui, Ibadur R.,Kehri, Harbans K.,Singh, Rana K. Pal
-
p. 4237 - 4245
(2013/05/08)
-
- One-pot, three component synthesis of 2,5-disubstituted 1,3,4-oxadiazoles catalyzed by heteropolyacid
-
H6[PMo9V3O40] was used as an efficient catalyst for the preparation of 1-aroyl-2-arylidene hydrazines. 2,5-Disubstituted 1,3,4-oxadiazoles have been synthesized by oxidation of 1-aroyl-2-arylidene hydrazines with CrO3 in excellent yields.
- Heravi, Majid M.,Zadsirjan, Vahideh,Bakhtiari, Khadijeh,Bamoharram, Fatemeh F.
-
p. 259 - 263
(2013/03/29)
-
- I2-mediated oxidative C-O bond formation for the synthesis of 1,3,4-oxadiazoles from aldehydes and hydrazides
-
A practical and transition-metal-free oxidative cyclization of acylhydrazones into 1,3,4-oxadiazoles has been developed by employing stoichiometric molecular iodine in the presence of potassium carbonate. The conditions of this cyclization reaction also work well with crude acylhydrazone substrates obtained from the condensation of aldehydes and hydrazides. A series of symmetrical and asymmetrical 2,5-disubstituted (aryl, alkyl, and/or vinyl) 1,3,4-oxadiazoles can be conveniently generated in an efficient and scalable fashion.
- Yu, Wenquan,Huang, Gang,Zhang, Yueteng,Liu, Hongxu,Dong, Lihong,Yu, Xuejun,Li, Yujiang,Chang, Junbiao
-
p. 10337 - 10343
(2013/11/06)
-
- Microwave-assisted one-step synthesis of 2,5-disubstituted-1,3,4- oxadiazoles using 1,4- bis(triphenylphosphonium)-2-butene peroxodisulfate
-
A series of 1,3,4-oxadiazoles were efficiently synthesized from the cyclization-oxidation reaction of acyl hydrazones by using 1,4- bis(triphenylphosphonium)-2-butene peroxodisulfate as an oxidant in solvent-free medium under microwave irradiation.
- Gorjizadeh, Maryam,Afshari, Mozhgan,Nazari, Simin
-
p. 1627 - 1630
(2014/05/06)
-
- 2,5-Disubstituted-1,3,4-oxadiazoles: Thymidine phosphorylase inhibitors
-
A series of 2,5-disubstituted-1,3,4-oxadiazoles (1-16) were synthesized via microwave irradiation and screened against thymidine phosphorylase enzyme. Four members of the series have demonstrated thymidine phosphorylase inhibitory activities with IC50 values between 37 and 320 μM. Pyridinyl-containing 1,3,4-oxadiazoles exhibited an enhanced inhibitory potential, while phenyl analogs did not show substantial inhibitory potential. Compound 9, a dipyridinyl residue having an IC50 value of 37 ± 0.76 μM was found to be the most potent in the series superior to standard inhibitor 7-deazaxanthine (IC50 = 39.28 ± 0.76 μM). Graphical abstract: [InlineMediaObject not available: see fulltext.]
- Khan, Khalid Mohammed,Rani, Mubeen,Ambreen, Nida,Ali, Muhammad,Hussain, Sajjad,Perveen, Shahnaz,Choudhary, Muhammad Iqbal
-
p. 6022 - 6028
(2013/11/06)
-
- Palladium-catalyzed direct arylation of N-heteroarenes with arylsulfonyl hydrazides
-
Hydrazides applied: A palladium-catalyzed direct Ci-H arylation of heteroarenes, with arylsulfonyl hydrazides as the arylating reagents, has been developed (see scheme). The reaction is chemoselective, in that arylsulfonyl hydrazides containing halogen substituents can be employed without participation of the halogen substituent in the reaction. The method offers a straightforward approach to a variety of aryl-heteroaryl compounds. Copyright
- Liu, Bo,Li, Jian,Song, Feijie,You, Jingsong
-
supporting information; experimental part
p. 10830 - 10833
(2012/09/22)
-
- Oxadiazoles in medicinal chemistry
-
Oxadiazoles are five-membered heteroaromatic rings containing two carbons, two nitrogens, and one oxygen atom, and they exist in different regioisomeric forms. Oxadiazoles are frequently occurring motifs in druglike molecules, and they are often used with the intention of being bioisosteric replacements for ester and amide functionalities. The current study presents a systematic comparison of 1,2,4- and 1,3,4-oxadiazole matched pairs in the AstraZeneca compound collection. In virtually all cases, the 1,3,4-oxadiazole isomer shows an order of magnitude lower lipophilicity (log D), as compared to its isomeric partner. Significant differences are also observed with respect to metabolic stability, hERG inhibition, and aqueous solubil ity, favoring the 1,3,4-oxadiazole isomers. The difference in profile between the 1,2,4 and 1,3,4 regioisomers can be rationalized by their intrinsically different charge distributions (e.g., dipole moments). To facilitate the use of these heteroaromatic rings, novel synthetic routes for ready access of a broad spectrum of 1,3,4-oxadiazoles, under mild conditions, are described.
- Bostr?m, Jonas,Hogner, Anders,Llinàs, Antonio,Wellner, Eric,Plowright, Alleyn T.
-
p. 1817 - 1830
(2012/05/05)
-
- Palladium-catalyzed deamidative arylation of azoles with arylamides through a tandem decarbonylation-C-H functionalization
-
A highly chemo-, regio-selective, and efficient palladium-catalyzed deamidative arylation of azoles with arylamides, as an aryl metal equivalent, has been developed. The reaction proceeds smoothly to generate the corresponding products in good yields via a tandem decarbonylation-C-H activation.
- Li, Chengliang,Li, Pinhua,Yang, Jin,Wang, Lei
-
supporting information; experimental part
p. 4214 - 4216
(2012/05/04)
-
- A highly efficient palladium-catalyzed desulfitative arylation of azoles with sodium arylsulfinates
-
A highly efficient palladium-catalyzed direct desulfitative arylation of azoles at C2-position has been developed using sodium arylsulfinates as aryl sources. Azoles including benzoxazoles, benzothiazoles, oxazoles, thiazoles, and 1,3,4-oxadiazoles reacted with sodium arylsulfinates smoothly to generate the corresponding products in good to excellent yields, and various substitution patterns were tolerated toward the reaction.
- Wang, Min,Li, Dengke,Zhou, Wei,Wang, Lei
-
experimental part
p. 1926 - 1930
(2012/03/26)
-
- 17O NMR studies of substituted 1,3,4-oxadiazoles
-
Three series of substituted 1,3,4-oxadiazoles were studied by 17O NMR spectroscopy. Chemical shifts values were correlated with empirical Hammett parameters as well as calculated bond lengths and chemical shielding values.
- Gierczyk, Blazej,Zalas, MacIej,Kazmierczak, Marcin,Grajewski, Jakub,Pankiewicz, Radoslaw,Wyrzykiewicz, Bozena
-
p. 648 - 654
(2012/01/06)
-
- Cu(II) catalyzed imine C-H functionalization leading to synthesis of 2,5-substituted 1,3,4-oxadiazoles
-
A direct access to symmetrical and unsymmetrical 2,5-disubstituted [1,3,4]-oxadiazoles has been accomplished through an imine C-H functionalization of N-arylidenearoylhydrazide using a catalytic quantity of Cu(OTf)2. This is the first example of amidic oxygen functioning as a nucleophile in a Cu-catalyzed oxidative coupling of an imine C-H bond. These reactions can be performed in air atmosphere and moisture making it exceptionally practical for application in organic synthesis.
- Guin, Srimanta,Ghosh, Tuhin,Rout, Saroj Kumar,Banerjee, Arghya,Patel, Bhisma K.
-
supporting information; experimental part
p. 5976 - 5979
(2012/01/02)
-
- N-chlorosuccinimide/1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)-mediated synthesis of 2,5-disubstituted 1,3,4-oxadiazoles
-
A mixture of N-chlorosuccinimide and 1,8-diazabicyclo[5.4.0]undec-7-ene oxidatively cyclizes structurally diverse acyl hydrazone, thereby providing an efficient and convenient method for the synthesis of various 2,5-disubstituted 1,3,4-oxadiazoles. The salient features of this method are mild reaction conditions, short reaction time, excellent yields, and simple workup procedure. Copyright
- Pardeshi, Santosh P.,Patil, Sachin S.,Bobade, Vivek D.
-
experimental part
p. 1601 - 1606
(2010/06/20)
-
- A palladium/copper bimetallic catalytic system: Dramatic improvement for Suzuki-Miyaura-type direct C-H arylation of azoles with arylboronic acids
-
Bimetallic catalytic system: Palladium/copper bimetallic-catalyzed Suzuki-Miyaura-type coupling has been disclosed for direct C-H arylation of azoles, instead of azole halides or pseudohalides, with arylboronic acids (see scheme).
- Liu, Bo,Qin, Xurong,Li, Kaizhi,Li, Xiyu,Guo, Qiang,Lan, Jingbo,You, Jingsong
-
supporting information; experimental part
p. 11836 - 11839
(2011/01/12)
-
- A novel, one-pot synthesis of 2,5-disubstituted-1,3,4-oxadiazoles using 1,4-bis(Triphenylphosphonium)-2-butene peroxodisulfate
-
An efficient and convenient synthesis of 1,3,4-oxadiazoles from aromatic aldehydes, acyl hydrazide, and 1,4- bis(triphenylphosphonium)-2-butene peroxodisulfate is reported. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.
- Badri, Rashid,Gorjizadeh, Maryam
-
experimental part
p. 544 - 549
(2010/06/12)
-
- Mild and convenient one-pot synthesis of 1,3,4-oxadiazoles
-
A mild, general, convenient, and efficient one-pot synthesis of 2-phenyl-5-substituted-1,3,4-oxadiazoles is described. Both (hetero)aryl and alkyl carboxylic acids were efficiently condensed with benzohydrazide in the presence of TBTU to give diacylhydrazine intermediates. The latter underwent a smooth TsCl-mediated cyclodehydration reaction to afford 2-phenyl-5-substituted- 1,3,4-oxadiazoles in good to very good yields.
- Stabile, Paolo,Lamonica, Alessandro,Ribecai, Arianna,Castoldi, Damiano,Guercio, Giuseppe,Curcuruto, Ornella
-
supporting information; experimental part
p. 4801 - 4805
(2010/10/02)
-
- A novel and direct synthesis of 1,3,4-oxadiazoles or oxazolines from carboxylic acids using cyanuric chloride/indium
-
Direct synthesis of various oxazolines and 1,3,4-oxadiazoles from carboxylic acids was achieved using cyanuric chloride/indium under very mild conditions.
- Kangani, Cyrous O.,Day, Billy W.
-
experimental part
p. 5332 - 5335
(2009/12/06)
-
- Trichloroisocyanuric acid-mediated one-pot synthesis of unsymmetrical 2,5-disubstituted 1,3,4-oxadiazoles at ambient temperature
-
An efficient method for the one-pot synthesis of unsymmetrical 2,5-disubstituted 1,3,4-oxadiazoles has been developed using trichloroisocyanuric acid (TCCA) at ambient temperature. A wide variety of aromatic as well as heterocyclic aldehydes exhibit condensation with a variety of acylhydrazines followed by oxidative cyclization to yield corresponding unsymmetrical 2,5-disubstituted 1,3,4-oxadiazoles. The mild nature of the synthesis and short reaction time are notable advantages of the developed protocol. Copyright Taylor & Francis Group, LLC.
- Pore,Mahadik,Desai
-
p. 3121 - 3128
(2008/12/22)
-
- A facile procedure for the one-pot synthesis of unsymmetrical 2,5-disubstituted 1,3,4-oxadiazoles
-
Unsymmetrically 2,5-disubstituted 1,3,4-oxadiazoles were efficiently synthesized from the cyclization-oxidation reaction of acyl hydrazones. Also, the synthesis of the title compounds was achieved by the condensation of acyl hydrazides and aromatic aldehydes in the presence of ceric ammonium nitrate in dichloromethane.
- Dabiri, Minoo,Salehi, Peyman,Baghbanzadeh, Mostafa,Bahramnejad, Mahboobeh
-
p. 6983 - 6986
(2007/10/03)
-
- One pot direct synthesis of oxazolines, benzoxazoles, and oxadiazoles from carboxylic acids using the Deoxo-Fluor reagent
-
A one-pot, high yield direct synthesis of various 2-substituted oxazolines, benzoxazoles, and 2-oxadiazoles from carboxylic acids using Deoxo-Fluor reagent is described.
- Kangani, Cyrous O.,Kelley, David E.,Day, Billy W.
-
p. 6497 - 6499
(2007/10/03)
-
- Microwave assisted syntheses of 2,5-disubstituted 1,3,4-oxadiazoles
-
2,5-Di-substituted 1,3,4-oxadiazoles have been synthesized from the oxidation of 1-aroyl-2-arylidene hydrazines with potassium permanganate on the surface of solid mineral support as well as in the mixture of acetone and water under microwave irradiation. 2,5-Disubstituted 1,3,4-oxadiazoles have been synthesized by oxidation of 1-aroyl-2-arylidene hydrazines with potassium permanganate on the surface of a solid mineral support as well as in mixtures of acetone and water under microwave irradiation.
- Rostamizadeh, Shahnaz,Housaini, S.A. Ghasem
-
p. 8753 - 8756
(2007/10/03)
-
- Facile synthesis of symmetric and unsymmetric 1,3,4-oxadiazoles using 2-acyl(or aroyl)pyridazin-3-ones
-
Symmetric and unsymmetric 1,3,4-oxadiazoles were synthesized in situ from hydrazine hydrate and the corresponding 2-acyl-4,5-dichloropyridazin-3-ones as acylating agents in polyphosphoric acid or BF3·OEt2 in excellent yields.
- Park, Yong-Dae,Kim, Jeum-Jong,Chung, Hyun-A,Kweon, Deok-Heon,Cho, Su-Dong,Lee, Sang-Gyeong,Yoon, Yong-Jin
-
p. 560 - 564
(2007/10/03)
-
- A new synthesis of 1,3,4-oxadiazoles. Cyclization of N,N'- diacylhydrazines catalyzed by palladium(0)
-
Several 1,3,4-oxadiazoles were synthetized by cyclization of N,N'- diacylhydrazines catalyzed by palladium(0). Water formed during the reaction is responsible for the hydrolysis of the products. To avoid it, we introduced benzoic anhydride into the medium and obtained an increased yield of oxadiazoles.
- Lutun, Stephane,Hasiak, Bruno,Couturier, Daniel
-
p. 111 - 116
(2007/10/03)
-
- TETRAZOLES IN THE SYNTHESES OF 1,3,4-OXADIAZOLES
-
Various variants of cleavage of tetrazoles to form 1,3,4-oxadiazoles are examined.The mechanisms and synthetic potentialities of these reactions are discussed.
- Koldobskii, G. I.,Ivanova, S. E.
-
p. 1512 - 1517
(2007/10/03)
-