- [4u202f+u202f1] Cyclization of benzohydrazide and ClCF2COONa towards 1,3,4-oxadiazoles and 1,3,4-oxadiazoles-d5
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A facile synthesis of 1,3,4-oxadiazoles and 1,3,4-oxadiazoles-d5 via [4 + 1] cyclization of ClCF2COONa with non-amine compounds containing amino groups is developed. Of note, this is the first time that halofluorinated compounds are used as C1 synthon to construct deuterated nitrogen-heterocyclic compounds. The current protocol features simple operation, readily accessible raw materials, wide substrate scope and valuable products
- Li, Xin,Mu, Shiqiang,Song, Qiuling,Wang, Ya
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supporting information
(2021/09/20)
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- Copper-Catalyzed Enantioconvergent Cross-Coupling of Racemic Alkyl Bromides with Azole C(sp2)?H Bonds
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The development of enantioconvergent cross-coupling of racemic alkyl halides directly with heteroarene C(sp2)?H bonds has been impeded by the use of a base at elevated temperature that leads to racemization. We herein report a copper(I)/cinchona-alkaloid-derived N,N,P-ligand catalytic system that enables oxidative addition with racemic alkyl bromides under mild conditions. Thus, coupling with azole C(sp2)?H bonds has been achieved in high enantioselectivity, affording a number of potentially useful α-chiral alkylated azoles, such as 1,3,4-oxadiazoles, oxazoles, and benzo[d]oxazoles as well as 1,3,4-triazoles, for drug discovery. Mechanistic experiments indicated facile deprotonation of an azole C(sp2)?H bond and the involvement of alkyl radical species under the reaction conditions.
- Chang, Xiao-Yong,Chen, Ji-Jun,Gu, Qiang-Shuai,Jiang, Sheng-Peng,Li, Zhong-Liang,Liu, Lin,Liu, Xiao-Dong,Liu, Xin-Yuan,Su, Xiao-Long,Wang, Fu-Li,Yang, Chang-Jiang,Ye, Liu
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supporting information
p. 380 - 384
(2020/10/30)
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- Functionalization of 1,3,4-Oxadiazoles and 1,2,4-Triazoles via Selective Zincation or Magnesiation Using 2,2,6,6-Tetramethylpiperidyl Bases
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We report the metalation of the 1,3,4-oxadiazole and 1,2,4-triazole scaffolds via regioselective zincation or magnesiation using the TMP bases (TMP = 2,2,6,6-tetramethylpiperidyl) TMP2Zn·2LiCl, TMP2Zn·2MgCl2·2LiCl, TMPMgCl
- Schw?rzer, Kuno,Tüllmann, Carl Phillip,Gra?l, Simon,Górski, Bartosz,Brocklehurst, Cara E.,Knochel, Paul
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supporting information
p. 1899 - 1902
(2020/03/03)
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- Ligand-Enabled Palladium-Catalyzed Through-Space C?H Bond Activation via a Carbopalladation/1,4-Pd Migration/C?H Functionalization Sequence
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We report, herein, a palladium-catalyzed cascade comprising carbopalladation, 1,4-Pd-migration and C(sp2)?C(sp2) bond formation to construct a variety of bis-heterocyclic frameworks in a single operational step. The methodology provi
- Chen, Su,Ranjan, Prabhat,Ramkumar, Nagarajan,Van Meervelt, Luc,Van der Eycken, Erik V.,Sharma, Upendra K.
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supporting information
p. 14075 - 14079
(2020/10/12)
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- Method for one-step construction of 2-(4-trifluoromethyl phenyl)-1,3,4-oxadiazole by taking DMF (dimethyl formamide) as carbon source
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The invention discloses a method for one-step construction of 2-(4-trifluoromethyl phenyl)-1,3,4-oxadiazole by taking DMF (dimethyl formamide) as a carbon source. In the method, p-trifluoromethyl benzoyl hydrazine is used as a reaction raw material, and t
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Paragraph 0012; 0016; 0023
(2019/01/17)
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- DMF as Methine Source: Copper-Catalyzed Direct Annulation of Hydrazides to 1,3,4-Oxadiazoles
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An unprecedented Cu-catalyzed direct annulation of hydrazides with N,N-dimethylformamide (DMF) was developed, providing an efficient synthesis of valuable 1,3,4-oxadiazoles. This process features the short reaction time and can be safely conducted on gram scale. The reaction also facilitated the convenient synthesis of 1,3,4-oxadiazole-2(3H)-ones. Moreover, the mechanistic studies suggest that the source of CH is from the N-methyl group of DMF. (Figure presented.).
- Wang, Shoucai,Wang, Kai,Kong, Xiangfei,Zhang, Shuhua,Jiang, Guangbin,Ji, Fanghua
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supporting information
p. 3986 - 3990
(2019/07/31)
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- Palladium-Catalyzed Domino Allenamide Carbopalladation/Direct C-H Allylation of Heteroarenes: Synthesis of Primprinine and Papaverine Analogues
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Palladium-catalyzed intramolecular carbopalladation onto allenamides completed by direct C-H allylation of heterocycles is studied. The domino construction/heteroarylation of isoquinolone process is first achieved. A general three-step one-pot strategy, i
- Hédouin, Jonathan,Schneider, Cédric,Gillaizeau, Isabelle,Hoarau, Christophe
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supporting information
p. 6027 - 6032
(2018/10/05)
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- (NHC)Cu-Catalyzed Mild C-H Amidation of (Hetero)arenes with Deprotectable Carbamates: Scope and Mechanistic Studies
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Primary arylamines are an important unit broadly found in synthetic, biological, and materials science. Herein we describe the development of a (NHC)Cu system that mediates a direct C-H amidation of (hetero)arenes by using N-chlorocarbamates or their sodio derivatives as the practical amino sources. A facile stoichiometric reaction of reactive copper-aryl intermediates with the amidating reagent led us to isolate key copper arylcarbamate species with the formation of a C-N bond. The use of tBuONa base made this transformation catalytic under mild conditions. The present (NHC)Cu-catalyzed C-H amidation works efficiently and selectively on a large scale over a range of arenes including polyfluorobenzenes, azoles, and quinoline N-oxides. Deprotection of the newly installed carbamate groups such as Boc and Cbz was readily performed to afford the corresponding primary arylamines.
- Xie, Weilong,Yoon, Jung Hee,Chang, Sukbok
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supporting information
p. 12605 - 12614
(2016/10/07)
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- Pd(OAc)2 catalyzed C-H activation of 1,3,4-oxadiazoles and their direct oxidative coupling with benzothiazoles and aryl boronic acids using Cu(OAc)2 as an oxidant
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The first direct oxidative coupling of 1,3,4-oxadiazoles with benzothiazoles has been accomplished using Pd(OAc)2 as a catalyst and Cu(OAc)2 as an oxidant. The similar combination of the catalyst and the oxidant has also been applied for direct arylation of 1,3,4-oxadiazoles with aryl boronic acids. Several novel oxadiazole derivatives have been prepared in high yields following both the methods.
- Salvanna,Reddy, Gandolla Chinna,Das, Biswanath
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supporting information
p. 2220 - 2225
(2013/03/13)
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- Transition metal-free direct C-H bond thiolation of 1,3,4-oxadiazoles and related heteroarenes
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A convenient transition metal-free procedure for the direct thiolation of 1,3,4-oxadiazole C-H bonds using diaryl disulfides has been developed. Other substrates including indole, benzothiazole, N-phenylbenzimidazole, and caffeine were also thiolated in this manner, providing the corresponding products in good to excellent yields. This journal is
- Zou, Liang-Hua,Reball, Jens,Mottweiler, Jakob,Bolm, Carsten
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p. 11307 - 11309,3
(2020/10/15)
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- Copper-catalyzed direct cross coupling of 1,3,4-oxadiazoles with trans-β-halostyrenes: Synthesis of 2-E-vinyl 1,3,4-oxadiazoles
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The first direct C-H alkenylation of 1,3,4-oxadiazoles with trans-β-halo olefinic system has been carried out using a combination of CuI/DMEDA as a catalyst. A wide range of 2-E-vinyl-substituted oxadiazoles were obtained in high yields (85-93%).
- Das, Biswanath,Reddy, Gandolla Chinna,Balasubramanyam, Penagaluri,Salvanna
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supporting information; experimental part
p. 300 - 305
(2012/01/05)
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- Copper-mediated C-H activation of 1,3,4-oxadiazoles with 1,1-dibromo-1-alkenes using PEG-400 as a solvent medium: Distinct approach for the alkynylation of 1,3,4-oxadiazoles
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The direct C-H alkynylation of 1,3,4-oxadiazoles with 1,1-dibromo-1-alkenes has been accomplished by using a combination of CuBr/LiOtBu in PEG-400 (a green solvent) at 80 °C. The products were formed in high yields (73-86%) in 2 h. No additional ligand or volatile solvent was required and the conversion was ecofriendly. The direct C-H alkynylation of 1,3,4-oxadiazoles with 1,1-dibromo-1-alkenes has been accomplished by using a combination of CuBr/LiOtBu in PEG-400 (a green solvent) at 80 °C. The products were formed in high yields (73-86%) in 2 h. No additional ligand or volatile solvent was required and the conversion was ecofriendly. Copyright
- Reddy, Gandolla Chinna,Balasubramanyam, Penagaluri,Salvanna,Das, Biswanath
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supporting information; experimental part
p. 471 - 474
(2012/03/08)
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- 17O NMR studies of substituted 1,3,4-oxadiazoles
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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
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p. 648 - 654
(2012/01/06)
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- Amination of benzoxazoles and 1,3,4-oxadiazoles using 2,2,6,6- tetramethylpiperidine-N-oxoammonium tetrafluoroborate as an organic oxidant
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No transition metals are necessary to convert benzoxazoles and 1,3,4-oxadiazoles into the corresponding pharmacologically interesting 2-aminated heterocycles by formal direct C(2)-amination using tetramethylpiperidine-N-oxoammonium tetrafluoroborate (TEMPO+BF 4-) as an oxidant (see scheme; TEMP=2,2,6,6- tetramethylpiperidine; TfOH=trifluoromethanesulfonic acid).
- Wertz, Sebastian,Kodama, Shintaro,Studer, Armido
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supporting information; experimental part
p. 11511 - 11515
(2012/01/11)
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- A metal-free route to 2-aminooxazoles by taking advantage of the unique ring opening of benzoxazoles and oxadiazoles with secondary amines
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Toss an amine into the ring: A new metal-free protocol for the amination of oxazoles has been developed by using iodobenzene diacetate to couple various oxazoles with amines (see scheme). The reaction proceeds through a ring-opening and subsequent ring-closing pathway. The optimal conditions are very mild and the substrate scope is broad, producing a range of 2-aminooxazoles, an important pharmacophore with high bioactivity. Copyright
- Joseph, Jomy,Kim, Ji Young,Chang, Sukbok
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supporting information; experimental part
p. 8294 - 8298
(2011/08/21)
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- Carbon dioxide as the C1 source for direct C-H functionalization of aromatic heterocycles
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(Equation Presented). A simple and straightforward method has been developed for the direct carboxylation of aromatic heterocylces such as oxazoles, thiazoles, and oxadiazoles using CO2 as the C1 source. The reactions require no metal catalyst and only Cs2CO3 as the base. A good functional group tolerance is achieved.
- Vechorkin, Oleg,Hirt, Nathalie,Hu, Xile
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supporting information; experimental part
p. 3567 - 3569
(2010/10/02)
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- Keto-1,3,4-oxadiazoles as cathepsin K inhibitors
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We have prepared a series of cathepsin K inhibitors bearing the keto-1,3,4-oxadiazole warhead capable of forming a hemithioketal complex with the target enzyme. By modifying binding moieties at the P1, P2, and prime side positions of the inhibitors, we have achieved selectivity over cathepsins B, L, and S, and have achieved sub-nanomolar potency against cathepsin K. This series thus represents a promising chemotype that could be used in diseases implicated by imbalances in cathepsin K activity such as osteoporosis.
- Palmer, James T.,Hirschbein, Bernard L.,Cheung, Harry,McCarter, John,Janc, James W.,Yu, Z. Walter,Wesolowski, Gregg
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p. 2909 - 2914
(2008/09/21)
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- TRIAZOLE, OXADIAZOLE AND THIADIAZOLE DERIVATIVE AS PPAR MODULATORS FOR THE TREATMENT OF DIABETES
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The present invention is directed to compounds represented by the following structural formula, Formula (I): wherein: (a) X is selected from the group consisting of a single bond, O, S, S(O)2 and N; (b) U is an aliphatic linker; (c) Y is selected from the group consisting of O, C, S, NH and a single bond; (d) W is N, O or S; (e) E is C(R3)(R4)A or A and wherein; (f) A is selected from the group consisting of carboxyl, tetrazole, C1-C6 alkylnitrile, carboxamide, sulfonamide and acylsufonamide. The other substituents are defined in the claims; the compounds are modulators of peroxisome proleferator activated receptors (PPARs) and are useful for the treatment of diabetes and other metabolic disorders.
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Page/Page column 84-85; 101; 111
(2008/06/13)
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