79476-07-6Relevant academic research and scientific papers
Metal-Free Deoxygenation of Amine N-Oxides: Synthetic and Mechanistic Studies
Lecroq, William,Schleinitz, Jules,Billoue, Mallaury,Perfetto, Anna,Gaumont, Annie-Claude,Lalevée, Jacques,Ciofini, Ilaria,Grimaud, Laurence,Lakhdar, Sami
, p. 1237 - 1242 (2021/06/01)
We report herein an unprecedented combination of light and P(III)/P(V) redox cycling for the efficient deoxygenation of aromatic amine N-oxides. Moreover, we discovered that a large variety of aliphatic amine N-oxides can easily be deoxygenated by using only phenylsilane. These practically simple approaches proceed well under metal-free conditions, tolerate many functionalities and are highly chemoselective. Combined experimental and computational studies enabled a deep understanding of factors controlling the reactivity of both aromatic and aliphatic amine N-oxides.
Complex Polyheterocycles and the Stereochemical Reassignment of Pileamartine A via Aza-Heck Triggered Aryl C-H Functionalization Cascades
Bower, John F.,Caiger, Lewis,García-Cárceles, Javier,Hazelden, Ian R.,Jones, Benjamin T.,Langer, Thomas,Lewis, Richard J.
supporting information, p. 15593 - 15598 (2021/10/12)
Structurally complex benzo- and spiro-fused N-polyheterocycles can be accessed via intramolecular Pd(0)-catalyzed alkene 1,2-aminoarylation reactions. The method uses N-(pentafluorobenzoyloxy)carbamates as the initiating motif, and this allows aza-Heck-type alkene amino-palladation in advance of C-H palladation of the aromatic component. The chemistry is showcased in the first total synthesis of the complex alkaloid (+)-pileamartine A, which has resulted in the reassignment of its absolute stereochemistry.
Design, Synthesis, and Antifungal Evaluation of Cryptolepine Derivatives against Phytopathogenic Fungi
Chen, Yong-Jia,Liu, Hua,Zhang, Shao-Yong,Li, Hu,Ma, Kun-Yuan,Liu, Ying-Qian,Yin, Xiao-Dan,Zhou, Rui,Yan, Yin-Fang,Wang, Ren-Xuan,He, Ying-Hui,Chu, Qing-Ru,Tang, Chen
, p. 1259 - 1271 (2021/02/16)
Inspired by the widely antiphytopathogenic application of diversified derivatives from natural sources, cryptolepine and its derivatives were subsequently designed, synthesized, and evaluated for their antifungal activities against four agriculturally important fungi Rhizoctonia solani, Botrytis cinerea, Fusarium graminearum, and Sclerotinia sclerotiorum. The results obtained from in vitro assay indicated that compounds a1-a24 showed great fungicidal property against B. cinerea (EC50 4 μg/mL); especially, a3 presented significantly prominent inhibitory activity with an EC50 of 0.027 μg/mL. In the pursuit of further expanding the antifungal spectrum of cryptolepine, ring-opened compound f1 produced better activity with an EC50 of 3.632 μg/mL against R. solani and an EC50 of 5.599 μg/mL against F. graminearum. Furthermore, a3 was selected to be a candidate to investigate its preliminary antifungal mechanism to B. cinerea, revealing that not only spore germination was effectively inhibited and the normal physiological structure of mycelium was severely undermined but also detrimental reactive oxygen was obviously accumulated and the normal function of the nucleus was fairly disordered. Besides, in vivo curative experiment against B. cinerea found that the therapeutic action of a3 was comparable to that of the positive control azoxystrobin. These results suggested that compound a3 could be regarded as a novel and promising agent against B. cinerea for its valuable potency.
Visible-Light-Photosensitized Aryl and Alkyl Decarboxylative Functionalization Reactions
Patra, Tuhin,Mukherjee, Satobhisha,Ma, Jiajia,Strieth-Kalthoff, Felix,Glorius, Frank
supporting information, p. 10514 - 10520 (2019/07/12)
Despite significant progress in aliphatic decarboxylation, an efficient and general protocol for radical aromatic decarboxylation has lagged far behind. Herein, we describe a general strategy for rapid access to both aryl and alkyl radicals by photosensitized decarboxylation of the corresponding carboxylic acids esters followed by their successive use in divergent carbon–heteroatom and carbon–carbon bond-forming reactions. Identification of a suitable activator for carboxylic acids is the key to bypass a competing single-electron-transfer mechanism and “switch on” an energy-transfer-mediated homolysis of unsymmetrical σ-bonds for a concerted fragmentation/decarboxylation process.
Halogen Bond-Assisted Electron-Catalyzed Atom Economic Iodination of Heteroarenes at Room Temperature
Kazi, Imran,Guha, Somraj,Sekar, Govindasamy
, p. 6642 - 6654 (2019/06/14)
A halogen bond-assisted electron-catalyzed iodination of heteroarenes has been developed for the first time under atom economic condition at room temperature. The iodination is successful with just 0.55 equiv of iodine and 0.50 equiv of peroxide. The kinetic study indicates that the reaction is elusive in the absence of a halogen bond between the substrate and iodine. The formation of a halogen bond, its importance in lowering the activation barrier for this reaction, the presence of radical intermediates in a reaction mixture, and the regioselectivity of the reaction have been demonstrated with several control experiments, spectroscopic analysis, and quantum chemical calculations. Allowing the formation of the halogen bond may offer a new strategy to generate the reactive radical intermediates and to enable the otherwise elusive electron-catalyzed reactions under mild reaction conditions.
A Novel Convenient Synthesis of Pyridinyl and Quinolinyl Triflates and Tosylates via One-Pot Diazotization of Aminopyridines and Aminoquinolines in Solution
Kassanova, Assiya Zh.,Krasnokutskaya, Elena A.,Beisembai, Perizat S.,Filimonov, Victor D.
, p. 256 - 262 (2016/01/15)
The first effective and simple method for the direct one-pot transformation of 2-, 3-, and 4-aminopyridines, 2,6-diaminopyridines, and 2-aminoquinoline into the corresponding pyridinyl and quinolinyl trifluoromethanesulfonates and tosylates in solvents was developed. The procedure involves diazotization of the heterocyclic amines with sodium nitrite in mixed hexane-DMSO or hexane-DMF solutions in the presence of trifluoromethanesulfonic acid or p-toluenesulfonic acid.
Copper-catalyzed conversion of aryl and heteroaryl bromides into the corresponding iodide
Feng, Xiujuan,Li, Lingyu,Yu, Xiaoqiang,Yamamoto, Yoshinori,Bao, Ming
, p. 129 - 132 (2016/07/06)
An efficient method for the synthesis of aryl and heteroaryl iodides is described in this study. The reactions of aryl and heteroaryl bromides with potassium iodide proceeded smoothly in the presence of a copper catalyst under mild reaction conditions to produce the corresponding iodides in satisfactory to excellent yields.
Metal-free synthesis of N-fused heterocyclic iodides via C-H functionalization mediated by tert-butylhydroperoxide
Sharma, Krishna K.,Patel, Dhananjay I.,Jain, Rahul
supporting information, p. 15129 - 15132 (2015/10/12)
Direct, regioselective and metal-free synthesis of fused N-heterocyclic iodides is reported. This regioselective C-H functionalization is mediated by tert-butylhydroperoxide (TBHP), via dual activation of molecular iodine and a heterocyclic substrate, resulting in the in situ generation of electrophilic iodine species (I+), and free radical(s) tBuO? or tBuOO?, driving the iodination reaction.
Regioselective, Molecular Iodine-Mediated C3 Iodination of Quinolines
Sun, Kai,Lv, Yunhe,Wang, Junjie,Sun, Jingjing,Liu, Lulu,Jia, Mingyang,Liu, Xin,Li, Zhenduo,Wang, Xin
supporting information, p. 4408 - 4411 (2015/09/28)
A novel and convenient method has been developed for the regioselective iodination of quinolines at their C3 position under metal-free conditions. Iodinated quinolines, which are popular building blocks in organic and medicinal chemistry, can be prepared in gram quantities and good yields using this method and further derivatized to give increasingly complex compounds. Preliminary mechanistic studies have shown that this reaction most likely occurs via a radical intermediate.
The regioselective iodination of quinolines, quinolones, pyridones, pyridines and uracil
Dutta, Uttam,Deb, Arghya,Lupton, David W.,Maiti, Debabrata
supporting information, p. 17744 - 17747 (2015/12/18)
A radical based direct C-H iodination protocol for quinolines, quinolones, pyridones, pyridines, and uracil has been developed. The iodination occurs in a C3 selective manner for quinolines and quinolones. Pyridones and pyridines undergo C3 and C5 iodination, while dimethyl uracil undergoes C5 iodination. Scope of the method was demonstrated through the rapid synthesis of both electron rich as well as electron poor heteroaromatic iodides. The protocol was found to be scalable and general, while a mechanism has been proposed.
