827-58-7Relevant articles and documents
Copper-Catalyzed Enantioconvergent Cross-Coupling of Racemic Alkyl Bromides with Azole C(sp2)?H Bonds
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
supporting information, p. 380 - 384 (2020/10/30)
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.
[4u202f+u202f1] Cyclization of benzohydrazide and ClCF2COONa towards 1,3,4-oxadiazoles and 1,3,4-oxadiazoles-d5
Li, Xin,Mu, Shiqiang,Song, Qiuling,Wang, Ya
supporting information, (2021/09/20)
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
Ligand-Enabled Palladium-Catalyzed Through-Space C?H Bond Activation via a Carbopalladation/1,4-Pd Migration/C?H Functionalization Sequence
Chen, Su,Ranjan, Prabhat,Ramkumar, Nagarajan,Van Meervelt, Luc,Van der Eycken, Erik V.,Sharma, Upendra K.
supporting information, p. 14075 - 14079 (2020/10/12)
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
TiCl4 mediated facile synthesis of 1,3,4-oxadiazoles and 1,3,4-thiadiazoles
Zhang, Lin,Yu, Yu,Tang, Qiang,Yuan, Jianyong,Ran, Dongzhi,Tian, Binghua,Pan, Tao,Gan, Zongjie
, p. 423 - 431 (2019/12/27)
An efficient method for the synthesis of 2,5-disubstituted 1,3,4-oxadiazoles and 1,3,4-thiadiazoles has been developed. Various hydrazides or thionyl hydrazides readily react with DMA derivatives in the presence of TiCl4 as a catalyst to afford the desired products. This protocol provides a simple and economical procedure that affords the target products with good yields and wide substrate scope.
Method for constructing 2-p-methylphenyl-1,3,4-oxadiazole by taking DMF as carbon source at one step
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Paragraph 0016-0023, (2019/02/26)
The invention discloses a method for constructing 2-p-methylphenyl-1,3,4-oxadiazole by taking DMF (N,N-dimethylformamide) as a carbon source at one step. The method comprises the following steps: taking p-methylbenzhydrazide as a reaction raw material; ta
DMF as Methine Source: Copper-Catalyzed Direct Annulation of Hydrazides to 1,3,4-Oxadiazoles
Wang, Shoucai,Wang, Kai,Kong, Xiangfei,Zhang, Shuhua,Jiang, Guangbin,Ji, Fanghua
supporting information, p. 3986 - 3990 (2019/07/31)
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.).
Palladium-Catalyzed Domino Allenamide Carbopalladation/Direct C-H Allylation of Heteroarenes: Synthesis of Primprinine and Papaverine Analogues
Hédouin, Jonathan,Schneider, Cédric,Gillaizeau, Isabelle,Hoarau, Christophe
supporting information, p. 6027 - 6032 (2018/10/05)
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
Synthesis of 1,3,4-Oxadiazoles via Annulation of Hydrazides and Benzene-1,3,5-triyl Triformate under Metal-Free Conditions
Yin, Zhiping,Power, Dennis J.,Wang, Zechao,Stewart, Scott G.,Wu, Xiao-Feng
supporting information, p. 3238 - 3242 (2018/04/24)
A new and efficient method for the synthesis of 1,3,4-oxadiazoles via the annulation of hydrazides with benzene-1,3,5-triyl triformate (TFBen) under metal-free conditions is reported. A broad range of hydrazides were transformed into the corresponding 1,3
Iodine-Mediated Domino Oxidative Cyclization: One-Pot Synthesis of 1,3,4-Oxadiazoles via Oxidative Cleavage of C(sp2)-H or C(sp)-H Bond
Fan, Yuxing,He, Yongqin,Liu, Xingxing,Hu, Ting,Ma, Haojie,Yang, Xiaodong,Luo, Xinliang,Huang, Guosheng
, p. 6820 - 6825 (2016/08/16)
An I2-promoted, metal-free domino protocol for one-pot synthesis of 1,3,4-oxadiazoles has been developed via oxidative cleavage of C(sp2)-H or C(sp)-H bonds, followed by cyclization and deacylation. In this reaction, the use of K2CO3 as a base is found to be an essential factor in the cyclization and the C-C bond cleavage. This procedure proceeded smoothly in moderate to high yields with good functional group compatibility.
