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.
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.
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.
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.
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
supporting information, 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.
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.).
Method for catalytically oxidizing amine to be synthesized into amide through dipyridyl-type manganese catalyst
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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.
C?N Cross-Coupling Reactions Under Mild Conditions Using Singlet Di-Radical Nickel(II)-Complexes as Catalyst: N-Arylation and Quinazoline Synthesis
Sikari, Rina,Sinha, Suman,Chakraborty, Gargi,Das, Siuli,van Leest, Nicolaas Petrus,Paul, Nanda D.
supporting information, p. 4342 - 4353 (2019/08/21)
Herein we report a cost-effective synthetic approach for C?N cross-coupling reactions of a broad array of nitrogen nucleophiles and aryl halides under mild conditions. These reactions are catalyzed by an inexpensive, air-stable, earth-abundant and easy-to-prepare singlet di-radical nickel(II)-catalyst containing two antiferromagnetically coupled single-electron oxidized diiminosemiquinonato type ligands. This protocol provides an alternative method for C?N cross-coupling reactions avoiding nickel(0)/nickel(II) or nickel(I)/nickel(III) redox processes via cooperative participation of metal and ligand-centered redox events. Besides a wide range of N-arylation reactions, by judicious choice of aryl halides and nitrogen nucleophiles the synthesis of a variety of polysubstituted quinazolines has been achieved in moderate to good yields under relatively mild reaction conditions. Our catalyst has been found to be almost equally effective in quinazoline synthesis via C?N cross-coupling of (i) 2-bromobenzylamine with benzamide, and (ii) 2-bromobenzylbromide with amidine. Control experiments and DFT studies were performed to improve the understanding of the cooperative participation of ligand and metal (nickel)-centered redox events during oxidative addition/reductive elimination processes of the catalytic cycle and to shed light on the plausible mechanistic pathway of the C?N cross-coupling reactions. (Figure presented.).
Iron-Catalyzed/Mediated C-N Bond Formation: Competition between Substrate Amination and Ligand Amination
Sinha, Suman,Sikari, Rina,Sinha, Vivek,Jash, Upasona,Das, Siuli,Brand?o, Paula,Demeshko, Serhiy,Meyer, Franc,De Bruin, Bas,Paul, Nanda D.
, p. 1935 - 1948 (2019/01/25)
Iron catalyzed carbon-nitrogen bond formation reactions of a wide variety of nucleophiles and aryl halides using well-defined iron-complexes featuring redox noninnocent 2-(arylazo)-1,10-phenanthroline (L1) ligands are reported. Besides substrate centered C-N coupling, C-N bond formation reactions were also observed at the ortho- and para-positions of the phenyl ring of the coordinated azo-aromatic scaffolds affording new tetradentate ligands, 2-N-aryl-(2-arylazo)-1,10-phenanthroline (L2), and tridentate ligands, 4-N-aryl-(2-arylazo)-1,10-phenanthroline (L3), respectively. Control experiments and mechanistic studies reveal that the complex [FeL1Cl2] (1) undergoes in situ reduction during the catalytic reaction to produce the monoanionic complex [1]-, which then acts as the active catalyst. The metal (iron) and the coordinated ligand were found to work in a cooperative manner during the transfer processes involved in the fundamental steps of the catalytic cycle. Detailed experimental and theoretical (DFT) studies were performed to get insight into the competitive substrate versus ligand centered amination reactions.
