32597-29-8Relevant academic research and scientific papers
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.
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.
Para -Selective copper-catalyzed C(sp2)-H amidation/dimerization of anilides via a radical pathway
Viveki, Amol B.,Garad, Dnyaneshwar N.,Gonnade, Rajesh G.,Mhaske, Santosh B.
supporting information, p. 1565 - 1568 (2020/02/13)
Copper-catalyzed amidation/dimerization of anilides via regioselective C(sp2)-H functionalization is achieved. The para-selective amidation is accomplished on the anilide aromatic ring via a radical pathway leading to C-N bond formation in the presence of ammonium persulfate as a radical source/oxidant for the copper catalyst. The developed protocol tolerates a wide range of anilide substrates. The regioselectivity is confirmed by single-crystal X-ray studies.
General rhodium-catalyzed oxidative cross-coupling reactions between anilines: Synthesis of unsymmetrical 2,2′-diaminobiaryls
Shi, Yang,Liu, Jiahui,Yang, Yudong,You, Jingsong
supporting information, p. 5475 - 5478 (2019/05/16)
Described herein is a dual chelation-assisted RhCl3-catalyzed oxidative C-H/C-H cross-coupling reaction of aniline derivatives. The highlight of this methodology is the chemo- and regioselective cross-coupling between electronically similar substrates, which represents a highly challenging task in oxidative Ar-H/Ar-H cross-coupling reactions. Furthermore, this Cp?-free catalytic reaction tolerates a range of functional groups and requires only a low molar ratio of coupling partners. These features expedite the synthesis of unsymmetrical 2,2′-diaminobiaryls.
Palladium(II)-Catalyzed Oxidative Homo- and Cross-Coupling of Aryl ortho -sp2 C-H Bonds of Anilides at Room Temperature
Mei, Chong,Lu, Wenjun
, p. 4812 - 4823 (2018/04/26)
The preparation of secondary 2,2'-bisanilides has been successfully achieved through an oxidative coupling of aryl ortho-sp2 C-H bonds of anilides in the presence of catalytic Pd(OAc)2 and K2S2O8 as an oxidant in MsOH/CF3CO2H (TFA) at room temperature (25 °C). The aromatic rings of anilides substituted by various electron-donating or electron-withdrawing groups are tolerant in these coupling reactions.
Sulfonium Salts as Alkylating Agents for Palladium-Catalyzed Direct Ortho Alkylation of Anilides and Aromatic Ureas
Simkó, Dániel Cs.,Elekes, Péter,Pázmándi, Vivien,Novák, Zoltán
supporting information, p. 676 - 679 (2018/02/09)
A novel method for the ortho alkylation of acetanilide and aromatic urea derivatives via C-H activation was developed. Alkyl dibenzothiophenium salts are considered to be new reagents for the palladium-catalyzed C-H activation reaction, which enables the transfer of methyl and other alkyl groups from the sulfonium salt to the aniline derivatives under mild catalytic conditions.
Oxidative C?H/C?H Cross-Coupling Reactions between N-Acylanilines and Benzamides Enabled by a Cp*-Free RhCl3/TFA Catalytic System
Shi, Yang,Zhang, Luoqiang,Lan, Jingbo,Zhang, Min,Zhou, Fulin,Wei, Wenlong,You, Jingsong
supporting information, p. 9108 - 9112 (2018/07/25)
By making use of a dual-chelation-assisted strategy, a completely regiocontrolled oxidative C?H/C?H cross-coupling reaction between an N-acylaniline and a benzamide has been accomplished for the first time. This process constitutes a step-economic and highly efficient pathway to 2-amino-2′-carboxybiaryl scaffolds from readily available substrates. A Cp*-free RhCl3/TFA catalytic system was developed to replace the [Cp*RhCl2]2/AgSbF6 system generally used in oxidative C?H/C?H cross-coupling reactions between two (hetero)arenes (Cp=pentamethylcyclopentadienyl, TFA=trifluoroacetic acid). The RhCl3/TFA system avoids the use of the expensive Cp* ligand and AgSbF6. As an illustrative example, the procedure developed herein greatly streamlines the total synthesis of the naturally occurring benzo[c]phenanthridine alkaloid oxynitidine, which was accomplished in excellent overall yield.
Rhodium(III)-catalysed, redox-neutral C(sp2)-H alkenylation using pivalimide as a directing group with internal alkynes
Kathiravan, Subban,Nicholls, Ian A.
supporting information, p. 1 - 4 (2016/12/23)
In the presence of [RhCp?Cl2]2, N-pivaloyl anilines react with internal alkynes to give the corresponding 2-alkenylpivalimides under redox neutral conditions through C-H activation. This redox neutral hydroarylation, which does not require an external organic acid, unlocks a regioselective synthetic route to 2-alkenyl anilines and is generally applicable to diversely substituted electron rich and electron poor pivalimides.
Visible-Light-Promoted C-H Arylation by Merging Palladium Catalysis with Organic Photoredox Catalysis
Jiang, Jian,Zhang, Wen-Man,Dai, Jian-Jun,Xu, Jun,Xu, Hua-Jian
, p. 3622 - 3630 (2017/04/11)
The use of a dual palladium/organic photoredox catalytic system enables the directed arylation of arenes with aryldiazonium salts with a broad substrate scope at room temperature under mild reaction conditions. This study thus serves as not only an alternative route for the biaryl motifs but also a new example for the application of an organic photoredox catalyst.
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.
