456-07-5Relevant academic research and scientific papers
Cu(II)-Catalyzed C-H Amidation/Cyclization of Azomethine Imines with Dioxazolones via Acyl Nitrenes: A Direct Access to Diverse 1,2,4-Triazole Derivatives
Liu, Xiang,Li, Wen,Jiang, Wenxuan,Lu, Hao,Liu, Jiali,Lin, Yijun,Cao, Hua
supporting information, p. 613 - 618 (2022/01/20)
We report a Cu(II)-catalyzed C-H amidation/cyclization of azomethine imines with dioxazolones as acyl nitrene transfer reagents under additive-and ligand-free conditions. An array of 1,2,4-triazolo[1,5-a]pyridine derivatives were afforded in moderate to good yields with excellent functional group tolerance. In addition, scale-up reaction and photoluminescence properties were discussed.
Palladium-Catalyzed 5-exo-dig Cyclization Cascade, Sequential Amination/Etherification for Stereoselective Construction of 3-Methyleneindolinones
Zuo, Youpeng,He, Xinwei,Tang, Qiang,Hu, Wangcheng,Zhou, Tongtong,Hu, Wenbo,Shang, Yongjia
, p. 2117 - 2123 (2020/12/22)
An cascade intramolecular 5-exo-dig cyclization of N-(2-iodophenyl)propiolamides and sequential amination/etherification (with N-hydroxybenzamides, phenyl hydroxycarbamate) protocol for the synthesis of amino- and phenoxy-substituted 3-methyleneindolinones using unexpensive Pd(PPh3)4 as catalyst has been developed. The protocol enables the assembly of structurally important oxindole cores featuring moderate functional group tolerance (particularly the halo group), affording a broad spectrum of products with diverse substituents in good to excellent yields. (Figure presented.).
Thioether-Directed NiH-Catalyzed Remote γ-C(sp3)-H Hydroamidation of Alkenes by 1,4,2-Dioxazol-5-ones
Chen, Qishu,Du, Bingnan,Ouyang, Yuxin,Yu, Wing-Yiu
supporting information, p. 14962 - 14968 (2021/09/29)
A NiH-catalyzed thioether-directed cyclometalation strategy is developed to enable remote methylene C-H bond amidation of unactivated alkenes. Due to the preference for five-membered nickelacycle formation, the chain-walking isomerization initiated by the NiH insertion to an alkene can be terminated at the γ-methylene site remote from the alkene moiety. By employing 2,9-dibutyl-1,10-phenanthroline as the ligand and dioxazolones as the reagent, the amidation occurs at the γ-C(sp3)-H bonds to afford the amide products in up to 90% yield (>40 examples) with remarkable regioselectivity (up to 24:1 rr).
Direct synthesis of benzoxazinones via Cp*Co(III)-catalyzed C–H activation and annulation of sulfoxonium ylides with dioxazolones
Yu, Yongqi,Xia, Zhen,Wu, Qianlong,Liu, Da,Yu, Lin,Xiao, Yuanjiu,Tan, Ze,Deng, Wei,Zhu, Gangguo
supporting information, p. 1263 - 1266 (2020/10/08)
A highly novel and direct synthesis of benzoxazinones was developed via Cp*Co(III)-catalyzed C–H activation and [3 + 3] annulation between sulfoxonium ylides and dioxazolones. The reaction is conducted under base-free conditions and tolerates various functional groups. Starting from diverse readily available sulfoxonium ylides and dioxazolones, a variety of benzoxazinones could be synthesized in one step in 32%-75% yields.
Synthesis of sulfimides and N-Allyl-N-(thio)amides by Ru(II)catalyzed nitrene transfer reactions of N-acyloxyamides
Zhang, Xinyu,Lin, Bo,Chen, Jianhui,Chen, Jiajia,Luo, Yanshu,Xia, Yuanzhi
supporting information, p. 819 - 825 (2021/02/01)
The N-acyloxyamides were employed as effective N-acyl nitrene precursors in reactions with thioethers under the catalysis of a commercially available Ru(II) complex, from which a variety of sulfimides were synthesized efficiently and mildly. If an allyl group is contained in the thioether precursor, the [2,3]-sigmatropic rearrangement of the sulfimide occurs simultaneously and the N-allyl-N-(thio)amides were obtained as the final products. Preliminary mechanistic studies indicated that the Ru-nitrenoid species should be a key intermediate in the transformation.
Palladium-catalyzed cascade decarboxylative amination/6- endo-dig benzannulation of o-alkynylarylketones with n-hydroxyamides to access diverse 1-naphthylamine derivatives
Zuo, Youpeng,He, Xinwei,Tang, Qiang,Hu, Wangcheng,Zhou, Tongtong,Shang, Yongjia
, p. 3890 - 3894 (2020/05/18)
An efficient and practical one-pot strategy to produce highly substituted 1-naphthylamines via sequential palladium-catalyzed decarboxylative amination/intramolecular 6-endo-dig benzannulation reactions has been described. In this reaction, a broad range of electron-rich, electron-neutral, and electron-deficient o-alkynylarylketones react well with N-hydroxyl aryl/alkylamides to give a diversity of 1-naphthylamines in good to excellent yields under mild reaction conditions. The gram-scale synthesis, with benefits such as undiminished product yield and easy transformation, illustrated the practicality of this method.
Divergent Synthesis of Tunable Cyclopentadienyl Ligands and Their Application in Rh-Catalyzed Enantioselective Synthesis of Isoindolinone
Cui, Wen-Jun,Wu, Zhi-Jie,Gu, Qing,You, Shu-Li
, p. 7379 - 7385 (2020/08/19)
A series of rhodium complexes bearing sterically and electronically tunable cyclopentadienyl ligands, prepared by utilizing Co2(CO)8-mediated [2+2+1] cyclization as a key step, were synthesized. In the presence of 2.5 mol% of CpmRh4, unprecedented enantioselective [4+1] annulation reaction of benzamides and alkenes was achieved with a broad substrate scope under mild reaction conditions, providing a variety of isoindolinones with excellent regio-and enantioselectivity (up to 94% yield, 97:3 er). Preliminary mechanistic studies suggest that the reaction involves an oxidative Heck reaction and an intramolecular enantioselective alkene hydroamination reaction.
RhIII-Catalyzed C?H Activation of Aryl Hydroxamates for the Synthesis of Isoindolinones
Shaaban, Saad,Davies, Caitlin,Merten, Christian,Flegel, Jana,Otte, Felix,Strohmann, Carsten,Waldmann, Herbert
supporting information, p. 10729 - 10734 (2020/07/25)
RhIII-catalyzed C?H functionalization reaction yielding isoindolinones from aryl hydroxamates and ortho-substituted styrenes is reported. The reaction proceeds smoothly under mild conditions at room temperature, and tolerates a range of functional groups. Experimental and computational investigations support that the high regioselectivity observed for these substrates results from the presence of an ortho-substituent embedded in the styrene. The resulting isoindolinones are valuable building blocks for the synthesis of bioactive compounds. They provide easy access to the natural-product-like compounds, isoindolobenzazepines, in a one-pot two-step reaction. Selected isoindolinones inhibited Hedgehog (Hh)-dependent differentiation of multipotent murine mesenchymal progenitor stem cells into osteoblasts.
Rhodium(III)-catalyzed C4-amidation of indole-oximes with dioxazolones: Via C-H activation
Deng, Ke-Zuan,Fu, Xiao-Pan,Ji, Ya-Fei,Tang, Shi-Biao,Wu, Gao-Rong,Xia, Cheng-Cai,Yang, Jin-Yue,Zhang, Li-Li
supporting information, p. 7922 - 7931 (2020/11/02)
A novel method for the Rh(III)-catalyzed oxime-directed C-H amidation of indoles with dioxazolones has been developed. This strategy provides an exclusive site selectivity and the directing group can be easily removed. This transformation features a wide substrate scope, good functional group tolerance and excellent yields, and may serve as a significant tool to construct structurally diverse indole derivatives for the screening of potential pharmaceuticals in the future. This journal is
Dioxazolones as masked ester surrogates in the Pd(ii)-catalyzed direct C-H arylation of 6,5-fused heterocycles
Saxena, Paridhi,Maida, Neha,Kapur, Manmohan
supporting information, p. 11187 - 11190 (2019/09/30)
A simple and effective Pd(ii)-catalyzed regioselective C(2)-H arylation of 6,5-fused heterocycles with dioxazolones as a masked ester surrogate under mild conditions is reported. The significance of the arylation is highlighted by the new reactivity demonstrated in dioxazolones via proximal C-H activation of the cyclic carbonate of the hydroxamic acid functionality under protic conditions.
