62662-74-2Relevant academic research and scientific papers
Nickel(II)- And Silver(I)-Catalyzed C-H Bond Halogenation of Anilides and Carbamates
Kianmehr, Ebrahim,Afaridoun, Hadi
, p. 1513 - 1523 (2020/12/14)
ortho -C-H bond halogenation of anilides and N -aryl carbamates using easily available N -halosuccinimides (NXS) as the active halogenation reagent in the presence of nickel or silver catalyst has been developed. This method provides a new approach to 2-haloanilides and carbamates, which may serve as starting materials for the synthesis of pharmaceutically and biologically active compounds.
Equivalent Loading of Directed Arenes in Pd(II)-Catalyzed Oxidative Cross-Coupling of Aryl C-H Bonds at Room Temperature
Mei, Chong,Zhao, Mengdi,Lu, Wenjun
, p. 2714 - 2733 (2021/02/01)
The unsymmetrical biaryls (Ar1-Ar2) produced by the catalytic cross-couplings of aryl halides (Ar1-halo) with aryl metallics (Ar2-M) in the loading ratio of 1:1 are popular in chemical synthesis. In contrast, there has been less precedence on the same biaryls produced effectively from two normal aryl C-H bonds with equivalent loading. Here, we report that, in a palladium/oxidant/acid catalytic system at room temperature, one arene (Ar1-H, 1 equiv) can highly selectively couple with the other one (Ar2-H, 1 equiv) to afford the target Ar1-Ar2 just by controlling the directing groups and the substituted groups on their phenyl rings. The utility of this one-one cross-coupling is also demonstrated by synthesis of a few bioactive molecules.
Novel and efficient heterogeneous polymer supported copper catalyst for synthesis of 2-substituted Benzoxazoles from 2-Haloanilides
Saranya, Thachora Venu,Sruthi, Pambingal Rajan,Raj, Veena,Anas, Saithalavi
supporting information, (2021/02/27)
A novel polymer supported copper complex is prepared by the immobilization of copper iodide on chemically modified polyacrylonitrile and its application in heterogeneous catalysis is described. The catalyst was prepared by easy method via synthetic modification of Polyacrylonitrile (PAN) using ethylene diamine followed by the complexation with CuI. After characterization, this complex was explored as a green and efficient heterogeneous catalyst for the synthesis of 2-benzoxazoles from 2-haloanilides. The reaction was performed without adding additional ligand and the catalyst shows activity over a broad range of substrates with quantitative product yields. The catalyst was easily recovered by simple filtration and reused successfully for further cycle.
Ligand Promoted Olefination of Anilides for Indirectly Introducing Fluorinated Functional Groups via Palladium Catalyst
Wang, Dongjie,Xu, Xu,Zhang, Jingyu,Zhao, Yingsheng
, p. 2696 - 2705 (2021/02/27)
We report a palladium-catalyzed, ligand promoted, C-H fluorine-containing olefination of anilides with 4-bromo-3,3,4,4-tetrafluorobutene as the fluorinated reagent, which has a potential transformation into other compounds due to its -CF2CF2Br functional group. -CF2CF2H was obtained by using the mild reducing agent sodium borohydride. Bioactive compounds such as aminoglutethimide derivative and propham were well-tolerated in this reaction, both of which highlight the synthetic importance of this method.
Synthesis method of 4-chloro-2-trifluoroacetylaniline hydrochloride hydrate
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Paragraph 0067-0073, (2019/10/01)
The invention provides a synthesis method of a 4-chloro-2-trifluoroacetylaniline hydrochloride hydrate. The synthesis method comprises the following steps of dissolving o-halogenated aniline in an organic solvent, then adding alkali, then adding an acylating agent, and carrying out an acylation reaction between the o-halogenated aniline and the acylating agent under an alkaline condition to obtaina compound I; carrying out a chlorination reaction between the compound I and a chlorinating agent under a weakly alkaline condition to obtain a compound II; adopting the compound II and magnesium for a reaction in an environment of inert gas to obtain a Grignard reagent intermediate, and carrying out a reaction between the Grignard reagent intermediate and a trifluoroacetic acid derivative to obtain a compound III; carrying out a reaction between the compound III and concentrated hydrochloric acid to obtain the 4-chloro-2-trifluoroacetylaniline hydrochloride hydrate. According to the synthesis method, the reaction condition is mild, the adopted raw materials are easy to obtain, the price is low, the total yield of the prepared target product can reach 80.35%, the purity can reach 99.8%,and the synthesis method is suitable for industrial production.
Site-Selective C–H Functionalization of (Hetero)Arenes via Transient, Non-symmetric Iodanes
Fosu, Stacy C.,Hambira, Chido M.,Chen, Andrew D.,Fuchs, James R.,Nagib, David A.
supporting information, p. 417 - 428 (2019/02/14)
Fosu, Hambira, and colleagues describe the direct C–H functionalization of medicinally relevant arenes or heteroarenes. This strategy is enabled by transient generation of reactive, non-symmetric iodanes from anions and PhI(OAc)2. The site-selective incorporation of Cl, Br, OMs, OTs, and OTf to complex molecules, including within medicines and natural products, can be conducted by the operationally simple procedure included herein. A computational model for predicting site selectivity is also included. The discovery of new medicines is a time- and labor-intensive process that frequently requires over a decade to complete. A major bottleneck is the synthesis of drug candidates, wherein each complex molecule must be prepared individually via a multi-step synthesis, frequently requiring a week of effort per molecule for thousands of candidates. As an alternate strategy, direct, post-synthetic functionalization of a lead candidate could enable this diversification in a single operation. In this article, we describe a new method for direct manipulation of drug-like molecules by incorporation of motifs with either known pharmaceutical value (halides) or that permit subsequent conversion (pseudo-halides) to medicinally relevant analogs. This user-friendly strategy is enabled by combining commercial iodine reagents with salts and acids. We expect this simple method for selective, post-synthetic incorporation of molecular diversity will streamline the discovery of new medicines. A strategy for C–H functionalization of arenes and heteroarenes has been developed to allow site-selective incorporation of various anions, including Cl, Br, OMs, OTs, and OTf. This approach is enabled by in situ generation of reactive, non-symmetric iodanes by combining anions and bench-stable PhI(OAc)2. The utility of this mechanism is demonstrated via para-selective chlorination of medicinally relevant arenes, as well as site-selective C–H chlorination of heteroarenes. Spectroscopic, computational, and competition experiments describe the unique nature, reactivity, and selectivity of these transient, unsymmetrical iodanes.
Facile synthesis of 2-benzoxazoles via CuI/2,2'-bipyridine catalyzed intramolecular C–O coupling of 2-haloanilides
Venu Saranya, Thachora,Rajan Sruthi, Pambingal,Anas, Saithalavi
supporting information, p. 297 - 307 (2019/01/18)
Development of newer methods for the synthesis of Benzoxazoles has of greater interest due to their wide range of biological activities and pharmaceutical importance. We herein report a facile and general method for the synthesis of 2-substituted Benzoxazoles via copper catalyzed intramolecular C–O cross-coupling of 2-haloanilides. A combination of CuI (5 mol%), 2,2'-bipyridine (10 mol%), Cs2CO3 (2 equiv.) in DMF solvent with 4 ? molecular sieves at 140 °C, illustrated the scope for tuning the reactivity of 2-haloanilides toward the selective formation of a series of 2-alkyl benzoxazole derivatives in moderate to good yields. This is the first systematic study using CuI/2,2'-Bipyridine as the catalytic system for the synthesis of 2-substituted Benzoxazoles. The outcome of the reaction was found to be significantly influenced by the aromatic and amide substituents of 2-haloanilides.
A preparing method of an efavirenz intermediate
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Paragraph 0026-0027, (2019/01/08)
The invention provides a preparing method of an efavirenz intermediate, and relates to the technical field of compound preparation methods. The method includes performing amino protection on 2-halogenaniline (II), as a raw material, with acyl chloride; reacting the generated N-acyl-2-halogen-aniline (III) with metal magnesium to generate a Grignard reagent; then reacting the Grignard reagent witha trifluoroacetyl amine compound (IV) to obtain N-acyl-2-(trifluoroacetyl)aniline (V); then reacting the N-acyl-2-(trifluoroacetyl)aniline (V) with chlorine under the function of a catalyst to obtainN-acyl-4-chloro-2-(trifluoroacetyl)aniline (VI); and performing hydrolysis and salting to obtain 4-chloro-2-(trifluoroacetyl)aniline hydrochloride hydrate (I). The method has characteristics of shortsynthetic steps, simple operation, high safety, a large raw material choosing range, and a high yield of the target product, and is suitable for large-scale industrial production.
A unified strategy for silver-, base-, and oxidant-free direct arylation of C-H bonds
Sahoo, Manoj K.,Midya, Siba P.,Landge, Vinod G.,Balaraman, Ekambaram
supporting information, p. 2111 - 2117 (2017/07/24)
Here, we report a dual catalytic approach for room temperature direct arylation of C-H bonds with aryldiazonium salts as a simple aryl group donor, also working as an internal oxidant via C-N2 bond cleavage. This unified strategy has been achieved by the synergistic combination of visible-light metal-free photoredox and palladium catalysis under silver-, base- and/or additive-free conditions. The broad substrate scope, functional group tolerance, excellent regioselectivity and redox-neutral conditions of this process make it attractive for the effective synthesis of a wide range of important N-heterocyclic commodities such as dibenzo[b,d]azepine, carbazole and phenanthridine.
Imidazolium Salt Catalyzed para -Selective Halogenation of Electron-Rich Arenes
Chen, Jie,Xiong, Xiaoyu,Chen, Zenghua,Huang, Jianhui
supporting information, p. 2831 - 2834 (2015/12/18)
A highly para-selective halogenation of arenes bearing coordinating groups in the presence of a dimidazolium salt as a catalyst is reported. A series of electron-rich p-haloarenes were prepared in good yields and good to excellent selectivities. We also propose a plausible mechanism for the catalytic reaction.
