4641-57-0Relevant academic research and scientific papers
Selective Cleavage and Tunable Functionalization of the C-C/C-N Bonds of N-Arylpiperidines Promoted by tBuONO
He, Yan,Zheng, Zhi,Liu, Yajie,Qiao, Jiajie,Zhang, Xinying,Fan, Xuesen
, p. 1676 - 1680 (2019)
In this paper, selective cleavage and tunable functionalization of the inert C-C/C-N bonds in N-arylpiperidines promoted by tBuONO under metal-free conditions is presented. To be specific, when the reaction was run in acetonitrile in the presence of molecular sieves, the synthetically useful acyclic N-formyl nitriles are formed. On the other hand, when alcohol was used as the reaction medium, the corresponding reactions afforded N-nitroso chain esters as dominating products via a mechanistically different pathway.
Electroselective and Controlled Reduction of Cyclic Imides to Hydroxylactams and Lactams
Bai, Ya,Shi, Lingling,Zheng, Lianyou,Ning, Shulin,Che, Xin,Zhang, Zhuoqi,Xiang, Jinbao
, p. 2298 - 2302 (2021/04/05)
An efficient and practical electrochemical method for selective reduction of cyclic imides has been developed using a simple undivided cell with carbon electrodes at room temperature. The reaction provides a useful strategy for the rapid synthesis of hydroxylactams and lactams in a controllable manner, which is tuned by electric current and reaction time, and exhibits broad substrate scope and high functional group tolerance even to reduction-sensitive moieties. Initial mechanistic studies suggest that the approach heavily relies on the utilization of amines (e.g., i-Pr2NH), which are able to generate α-aminoalkyl radicals. This protocol provides an efficient route for the cleavage of C-O bonds under mild conditions with high chemoselectivity.
A ligand-free copper-catalyzed strategy to the N-arylation of indazole using aryl bromides
Bai, Di-Xiang,Lim, Rachel Sin-Ee,Ng, Hui-Fen,Teo, Yong-Chua
supporting information, p. 1398 - 1405 (2021/03/08)
A simple and efficient strategy for the C–N cross-coupling of indazole with a variety of substituted aryl bromides is reported. Under the optimized conditions, a broad scope of N-arylated products were obtained in good to excellent yields (up to 87%) under the ligand-free conditions.
Minimization of Back-Electron Transfer Enables the Elusive sp3 C?H Functionalization of Secondary Anilines
Zhao, Huaibo,Leonori, Daniele
supporting information, p. 7669 - 7674 (2021/03/08)
Anilines are some of the most used class of substrates for application in photoinduced electron transfer. N,N-Dialkyl-derivatives enable radical generation α to the N-atom by oxidation followed by deprotonation. This approach is however elusive to monosubstituted anilines owing to fast back-electron transfer (BET). Here we demonstrate that BET can be minimised by using photoredox catalysis in the presence of an exogenous alkylamine. This approach synergistically aids aniline SET oxidation and then accelerates the following deprotonation. In this way, the generation of α-anilinoalkyl radicals is now possible and these species can be used in a general sense to achieve divergent sp3 C?H functionalization.
Phenyl 4-(2-oxopyrrolidin-1-yl)benzenesulfonates and phenyl 4-(2-oxopyrrolidin-1-yl)benzenesulfonamides as new antimicrotubule agents targeting the colchicine-binding site
Gagné-Boulet, Mathieu,Bouzriba, Chahrazed,Chavez Alvarez, Atziri Corin,Fortin, Sébastien
, (2021/01/20)
We recently designed and prepared new families of potent antimicrotubule agents designated as N-phenyl 4-(2-oxoimidazolidin-1-yl)benzenesulfonates (PIB–SOs) and phenyl 4-(2-oxoimidazolidin-1-yl)benzenesulfonamides (PIB–SAs). Our previous structure-activity relationship studies (SAR) focused on the aromatic ring B of PIB-SOs and PIB-SAs leaving the impact of the phenylimidazolidin-2-one moiety (ring A) on the binding to the colchicine-binding site (C-BS) poorly studied. Therefore, the aim of the present study was to evaluate the effect of replacing the imidazolidin-2-one (IMZ) group by a pyrrolidin-2-one moiety. To that end, 15 new phenyl 4-(2-oxopyrrolidin-1-yl)benzenesulfonate (PYB–SO) and 15 phenyl 4-(2-oxopyrrolidin-1-yl)benzenesulfonamide (PYB-SA) derivatives were designed, prepared, chemically characterised and biologically evaluated. PYB-SOs and PYB-SAs exhibit antiproliferative activity in the low nanomolar to low micromolar range (0.0087–8.6 μM and 0.056–21 μM, respectively) on human HT-1080, HT-29, M21 and MCF7 cancer cell lines. Moreover, they block cell cycle progression in G2/M phase. Immunofluorescence, tubulin affinity and tubulin polymerisation assays show that they cause microtubule depolymerisation by docking the C-BS. In addition, docking assays with the most potent derivatives show binding affinity toward the C-BS and they also exhibit weak or no toxicity toward chick embryos. Finally, physicochemical properties calculated using the SwissADME algorithm show that PYB-SOs and PYB-SAs are promising new families of antimicrotubule agents.
Air- And moisture-stable Xantphos-ligated palladium dialkyl complex as a precatalyst for cross-coupling reactions
Takahashi, Rina,Kubota, Koji,Ito, Hajime
supporting information, p. 407 - 410 (2020/01/13)
Although xantphos has been employed in a variety of palladium-catalyzed cross-coupling reactions, there has been little progress in developing Xantphos-ligated precatalysts. In this report, we describe a Xantphos-ligated palladium dialkyl complex that acts as a powerful precatalyst for C-N, C-S, and C-C cross-coupling reactions. This precatalyst is air- and moisture stable but can be thermally activated in the absence of external reagents. Additionally, potential catalyst inhibitors are not generated during the precatalyst activation. This complex thus represents a convenient alternative to previously reported classes of Xantphos-ligated precatalysts.
Synthesis of Aliphatic Amides through a Photoredox Catalyzed Radical Carbonylation Involving Organosilicates as Alkyl Radical Precursors
Cartier, Alex,Levernier, Etienne,Dhimane, Anne-Lise,Fukuyama, Takahide,Ollivier, Cyril,Ryu, Ilhyong,Fensterbank, Louis
, p. 2254 - 2259 (2020/05/06)
Alkyl radicals, from primary to tertiary, formed by photocatalyzed oxidation of organosilicates, are involved efficiently in radical carbonylation with carbon monoxide (CO), in the presence of various amines and CCl4, leading to a variety of amides in moderate to good yields. (Figure presented.).
Highly-chemoselective step-down reduction of carboxylic acids to aromatic hydrocarbons: Via palladium catalysis
Liu, Chengwei,Qin, Zhi-Xin,Ji, Chong-Lei,Hong, Xin,Szostak, Michal
, p. 5736 - 5742 (2019/06/18)
Aryl carboxylic acids are among the most abundant substrates in chemical synthesis and represent a perfect example of a traceless directing group that is central to many processes in the preparation of pharmaceuticals, natural products and polymers. Herein, we describe a highly selective method for the direct step-down reduction of carboxylic acids to arenes, proceeding via well-defined Pd(0)/(ii) catalytic cycle. The method shows a remarkably broad substrate scope, enabling to direct the classical acyl reduction towards selective decarbonylation by a redox-neutral mechanism. The utility of this reaction is highlighted in the direct defunctionalization of pharmaceuticals and natural products, and further emphasized in a range of traceless processes using removable carboxylic acids under mild, redox-neutral conditions orthogonal to protodecarboxylation. Extensive DFT computations were conducted to demonstrate preferred selectivity for the reversible oxidative addition and indicated that a versatile hydrogen atom transfer (HAT) pathway is operable.
Method for catalytically oxidizing amine to be synthesized into amide through dipyridyl-type manganese catalyst
-
Paragraph 0017-0027; 0046-0048, (2019/06/30)
The invention discloses a methodfor catalytically oxidizing amine to be synthesized into amide througha dipyridyl-type manganese catalyst. According to the method, a dipyridyl manganese complex formedafter coordination of a dipyridyl-type complex and cheap metal manganese serves as the catalyst, clean and environment-friendly hydrogen peroxide serves as an oxidizing agent, oxidation of N ortho-position sp3 C-H bonds catalyzed by the cheap metal manganese is achieved, and the amine is directly oxidized to obtain the amide. Compared with existing methods, the method has the advantages that theadopted catalyst is low in price, the preparing method is simple, raw materials are easy to obtain, the use level of the catalyst is low, the substrate range is wide, the reaction condition is mild, the operation is simple and environmentally friendly, the reaction time is short, the yield is high, the selectivity is high, and the industrialization cost is low.
Single-Electron-Transfer-Induced C(sp3)-N Couplings via C-C Bond Cleavage of Cycloketoxime Esters
Shi, Zhuangzhi,Wang, Minyan,Zhao, Binlin
, (2019/08/26)
A practical single-electron-transfer-induced selective C(sp3)-N coupling of cycloketoximes with anilines via C-C bond cleavage under copper-catalytic and synergetic photoredox/copper-catalytic reaction systems has been uncovered. These two powerful and simple protocols demonstrated excellent selectivity and good functional group compatibility without any base or ligand control. Preliminary mechanistic experiments indicated that a radical-mediated process was involved in these transformations.
