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1.
Organocatalytic Asymmetric Friedel–Crafts Reaction of Sesamol with Isatins: Access to Biologically Relevant 3‐Aryl‐3‐hydroxy‐2‐oxindoles 下载免费PDF全文
Dr. Akshay Kumar Jasneet Kaur Dr. Pankaj Chauhan Prof. Dr. Swapandeep Singh Chimni 《化学:亚洲杂志》2014,9(5):1305-1310
The Friedel–Crafts reaction of electron‐rich phenols with isatins was developed by employing bifunctional thiourea–tertiary amine organocatalysts. Cinchona alkaloid derived thiourea epiCDT‐ 3 a efficiently catalyzed the Friedel–Crafts‐type addition of phenols to isatin derivatives to provide 3‐aryl‐3‐hydroxy‐2‐oxindoles 7 and 9 in good yield (80–95 %) with good enantiomeric excess (83–94 %). Friedel–Crafts adduct 7 t was subjected to a copper(I)‐catalyzed azide–alkyne cycloaddition to obtain biologically important 3‐aryl‐3‐hydroxy‐2‐oxindole 11 in good enantiomeric excess and having a 1,2,3‐triazole moiety. 相似文献
2.
Morteza Shiri Mohammad Ali Zolfigol Atefeh Shamsian Ahmad Ali Dehghani‐Firouzabadi 《Journal of heterocyclic chemistry》2012,49(6):1429-1433
Syntheses of polyindolyl compounds from the Friedel–Crafts reaction of indoles and tri‐ or tetra‐aldehydes catalyzed by silica sulfuric acid are described. These dendrimeric supramolecules were effectively prepared at room temperature in quantitative yield. These novel products have potential in the synthesis of dyes and pigments and also in various pharmaceutical applications. 相似文献
3.
Structurally Divergent Lithium Catalyzed Friedel–Crafts Reactions on Oxetan‐3‐ols: Synthesis of 3,3‐Diaryloxetanes and 2,3‐Dihydrobenzofurans 下载免费PDF全文
Rosemary A. Croft Dr. James J. Mousseau Chulho Choi Dr. James A. Bull 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(45):16271-16276
The first examples of 3,3‐diaryloxetanes are prepared in a lithium‐catalyzed and substrate dependent divergent Friedel–Crafts reaction. para‐Selective Friedel–Crafts reactions of phenols using oxetan‐3‐ols afford 3,3‐diaryloxetanes by displacement of the hydroxy group. These constitute new isosteres for benzophenones and diarylmethanes. Conversely, ortho‐selective Friedel–Crafts reactions of phenols afford 3‐aryl‐3‐hydroxymethyl‐dihydrobenzofurans by tandem alkylation–ring‐opening reactions; the outcome of the reaction diverging to structurally distinct products dependent on the substrate regioselectivity. Further reactivity of the oxetane products is demonstrated, suitable for incorporation into drug discovery efforts. 相似文献
4.
Enantioselective and Regiodivergent Functionalization of N‐Allylcarbamates by Mechanistically Divergent Multicatalysis 下载免费PDF全文
Dr. Edward Richmond Ismat Ullah Khan Dr. Joseph Moran 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(35):12274-12277
A pair of mechanistically divergent multicatalytic reaction sequences has been developed consisting of nickel‐catalyzed isomerization of N‐allylcarbamates and subsequent phosphoric‐acid‐catalyzed enantioselective functionalization of the resulting intermediates. By appropriate selection of reaction partners, in situ generated imines and ene‐carbamates are mechanistically partitioned to yield opposing functionalized products. Formal α‐functionalization to give protected α‐arylamines is achieved upon enantioselective Friedel–Crafts reaction with arene nucleophiles, whereas formal β‐functionalization is achieved upon reaction with diarylimine electrophiles in an enantioselective Povarov‐[4+2] cycloaddition. 相似文献
5.
Mild Friedel–Crafts Reactions inside a Hexameric Resorcinarene Capsule: C−Cl Bond Activation through Hydrogen Bonding to Bridging Water Molecules 下载免费PDF全文
Pellegrino La Manna Dr. Carmen Talotta Giuseppe Floresta Dr. Margherita De Rosa Prof. Dr. Annunziata Soriente Prof. Dr. Antonio Rescifina Prof. Dr. Carmine Gaeta Prof. Dr. Placido Neri 《Angewandte Chemie (International ed. in English)》2018,57(19):5423-5428
A novel catalytic feature of a hexameric resorcinarene capsule is highlighted. The self‐assembled cage was exploited to promote the Friedel–Crafts benzylation of several arenes and heteroarenes with benzyl chloride under mild conditions. Calculations showed that there are catalytically relevant hydrogen‐bonding interactions between the bridging water molecules of the capsule and benzyl chloride, which is fundamental for the activation of the C?Cl bond. The capsule controls the reaction outcome. Inside the inner cavity of the capsule, N‐methylpyrrole is preferentially benzylated in the unusual β‐position while mesitylene reacts faster than 1,3‐dimethoxybenzene despite the greater π‐nucleophilicity of the latter compound. 相似文献
6.
Asymmetric Dearomatization of Indoles through a Michael/Friedel–Crafts‐Type Cascade To Construct Polycyclic Spiroindolines 下载免费PDF全文
Xiaohu Zhao Prof. Xiaohua Liu Hongjiang Mei Jing Guo Dr. Lili Lin Prof. Xiaoming Feng 《Angewandte Chemie (International ed. in English)》2015,54(13):4032-4035
A highly efficient asymmetric dearomatization of indoles was realized through a cascade reaction between 2‐isocyanoethylindole and alkylidene malonates catalyzed by a chiral N,N′‐dioxide/MgII catalyst. Fused polycyclic indolines containing three stereocenters were afforded in good yields with excellent diastereo‐ and enantioselectivities through a Michael/Friedel–Crafts/Mannich cascade. When 2‐substituted 2‐isocyanoethylindoles were used, spiroindoline derivatives were obtained through a Michael/Friedel–Crafts reaction. 相似文献
7.
Friedel‐Crafts alkylation of indoles with nitroalkenes catalyzed by a novel Zn(II)‐thiourea complex has been developed. The remarkable advantages of this reaction are mild reaction conditions, simple workup procedure, high yield of products and the use of ethanol as acceptable solvent. 相似文献
8.
Lewis Acid Catalyzed Enantioselective Desymmetrization of Donor–Acceptor meso‐Diaminocyclopropanes 下载免费PDF全文
Daniele Perrotta Ming‐Ming Wang Prof. Dr. Jérôme Waser 《Angewandte Chemie (International ed. in English)》2018,57(18):5120-5123
The first Lewis acid catalyzed enantioselective ring‐opening desymmetrization of a donor–acceptor meso‐diaminocyclopropane is reported. The copper(II)‐catalyzed Friedel–Crafts alkylation of indoles and one pyrrole with an unprecedented meso‐diaminocyclopropane delivered enantioenriched, diastereomerically pure urea products, which are structurally related to natural and synthetic bioactive compounds. The development of a new ligand through the investigation of an underexplored subclass of bis(oxazoline) ligands was essential for achieving high enantioselectivities. 相似文献
9.
Branch‐Selective Alkene Hydroarylation by Cooperative Destabilization: Iridium‐Catalyzed ortho‐Alkylation of Acetanilides 下载免费PDF全文
Giacomo E. M. Crisenza Olga O. Sokolova Dr. John F. Bower 《Angewandte Chemie (International ed. in English)》2015,54(49):14866-14870
An iridium(I) catalyst system, modified with the wide‐bite‐angle and electron‐deficient bisphosphine dFppb (1,4‐bis(di(pentafluorophenyl)phosphino)butane) promotes highly branch‐selective hydroarylation reactions between diverse acetanilides and aryl‐ or alkyl‐substituted alkenes. This provides direct and ortho‐selective access to synthetically challenging anilines, and addresses long‐standing issues associated with related Friedel–Crafts alkylations. 相似文献
10.
Stereocontrolled Syntheses of Tetralone‐ and Naphthyl‐Type Lignans by a One‐Pot Oxidative [3,3] Rearrangement/Friedel–Crafts Arylation 下载免费PDF全文
Jordan C. T. Reddel Kelly E. Lutz Abdallah B. Diagne Prof. Regan J. Thomson 《Angewandte Chemie (International ed. in English)》2014,53(5):1395-1398
The development of a stereoselective one‐pot oxidative [3,3] sigmatropic rearrangement/Friedel–Crafts arylation that provides enantioenriched benzhydryl compounds is reported. The utility of this new transformation is demonstrated by the concise synthesis of several tetralone‐ and naphthyl‐type lignan natural products, many of which display anti‐malarial activity. 相似文献
11.
Iron(III)‐Catalyzed Arylation of Spiro‐Epoxyoxindoles with Phenols/Naphthols towards the Synthesis of Spirocyclic Oxindoles 下载免费PDF全文
Mupeng Luo Rongju Yuan Xuesong Liu Linqian Yu Prof. Wanguo Wei 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(28):9797-9803
An efficient and highly regioselective iron(III)‐catalyzed Friedel–Crafts‐type arylation of spiro‐epoxyoxindoles with phenols was developed for rapid access to 3‐(3‐indolyl)‐oxindole‐3‐methanols, which could be further elaborated into benzofuranyl‐spirooxindoles under Mitsunobu conditions. When spiro‐epoxyoxindoles were reacted with naphthols in the presence of a catalytic amount of FeCl3?6 H2O in dichloromethane, they underwent a tandem Friedel–Crafts‐type arylation and O‐cyclization to yield novel naphthofuranyl‐spirooxindoles in excellent yields. This method is applied to enable the efficient and highly regioselective synthesis of a small‐molecule inhibitor of the sodium channel Nav1.7 (±)‐XEN402, which is currently in a phase IIb clinical trial for the treatment of pain. 相似文献
12.
New Chiral Reagent for Installation of Pharmacophoric (S)‐ or (R)‐2‐(Alkoxyphosphono)‐1‐amino‐2,2‐difluoroethyl Groups 下载免费PDF全文
Chen Xie Lijun Zhang Dr. Haibo Mei Dr. Romana Pajkert Dr. Maksym Ponomarenko Dr. Yi Pan Prof. Dr. Gerd‐Volker Röschenthaler Prof. Dr. Vadim A. Soloshonok Dr. Jianlin Han 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(21):7036-7040
A new chiral reagent has been developed for generalized installation of pharmacophoric (S)‐ or (R)‐2‐(alkoxyphosphono)‐1‐amino‐2,2‐difluoroethyl group into organic compounds. The original synthetic application of this new reagent is exemplified by Friedel–Crafts reactions with indoles, which proceed efficiently with excellent diastereoselectivity to give enantiomerically pure products. 相似文献
13.
Dr. Zhiwei Jiao Dr. Li Hui Lim Prof. Dr. Hajime Hirao Prof. Dr. Jianrong Steve Zhou 《Angewandte Chemie (International ed. in English)》2018,57(21):6294-6298
Intermolecular alkylations of electron‐deficient arenes proceed with good para selectivity. Palladium catalysts were used to generate nucleophilic alkyl radicals from alkyl halides, which then directly add onto the arenes. The arene scope and the site of alkylation are opposite to those of classical Friedel–Crafts alkylations, which prefer electron‐rich systems. 相似文献
14.
Biaryl Synthesis by Ring‐Opening Friedel–Crafts Arylation of 1,4‐Epoxy‐1,4‐dihydronaphthalenes Catalyzed by Iron Trichloride 下载免费PDF全文
Dr. Yoshinari Sawama Shota Asai Takahiro Kawajiri Dr. Yasunari Monguchi Prof. Dr. Hironao Sajiki 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(5):2222-2229
Biaryl and heterobiaryl compounds are important frameworks across a range of fields including pharmaceutical and functional material chemistries. We have accomplished the efficient synthesis of various naphthalene‐linked arenes and heteroarenes as biaryls and heterobiaryls by the FeCl3‐catalyzed Friedel‐Crafts reactions accompanied by the ring‐opening of the 1,4‐epoxy moiety of 1,4‐epoxy‐1,4‐dihydronaphthalenes. Especially, it is noteworthy that 1‐silylated substrates were regioselectively transformed to the 3‐aryl‐1‐silylnaphthalenes and the double Friedel–Crafts reactions using thiophene derivatives could directly produce the corresponding bis‐naphthlated thiophene derivatives. 相似文献
15.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(26):7723-7727
The Friedel–Crafts acylation is commonly used for the synthesis of aryl ketones, and a biocatalytic version, which may benefit from the chemo‐ and regioselectivity of enzymes, has not yet been introduced. Described here is a bacterial acyltransferase which can catalyze Friedel–Crafts C‐acylation of phenolic substrates in buffer without the need of CoA‐activated reagents. Conversions reach up to >99 %, and various C‐ or O‐acyl donors, such as DAPG or isopropenyl acetate, are accepted by this enzyme. Furthermore the enzyme enables a Fries rearrangement‐like reaction of resorcinol derivatives. These findings open an avenue for the development of alternative and selective C−C bond formation methods. 相似文献
16.
Haifeng Zheng Kuiyong Dong Daniel Wherritt Hadi Arman Michael P. Doyle 《Angewandte Chemie (International ed. in English)》2020,59(32):13613-13617
The direct Friedel–Crafts‐type coupling and dedinitrogenation reactions of vinyldiazo compounds with aromatic compounds using a metal‐free strategy are described. This Brønsted acid catalyzed method is efficient for the formation of α‐diazo β‐carbocations (vinyldiazonium ions), vinyl carbocations, and allylic or homoallylic carbocation species via vinyldiazo compounds. By choosing suitable nucleophilic reagents to selectively capture these intermediates, both trisubstituted α,β‐unsaturated esters, β‐indole‐substituted diazo esters, and dienes are obtained with good to high yields and selectivity. Experimental insights implicate a reaction mechanism involving the selective protonation of vinyldiazo compounds and the subsequent release of dinitrogen to form vinyl cations that undergo intramolecular 1,3‐ and 1,4‐ hydride transfer processes as well as fragmentation. 相似文献
17.
Amine‐Catalyzed Highly Regioselective and Stereoselective C(sp2)–C(sp2) Cross‐Coupling of Naphthols with trans‐α,β‐Unsaturated Aldehydes 下载免费PDF全文
A metal‐free C(sp2)–C(sp2) cross‐coupling approach to highly congested (E)‐α‐naphtholylenals from simple naphthols and enals is described. The mild reaction conditions with pyridine hydrobromideperbromide (PHBP) as the bromination reagent in the presence of piperidine or diphenylprolinol trimethylsilyl (TMS) ether as promoters enable the process in good yields and with high chemoselectivity, regioselectivity, and stereoselectivity. The process involves an unprecedented pathway of in situ regioselective 4‐bromination of 1‐naphthols and the subsequent unusual aromatic nucleophilic substitution of the resulting 4‐bromo‐1‐naphthols with the α‐C(sp2) of enals through a Michael‐type Friedel–Crafts alkylation–dearomatization followed by a cyclopropanation ring‐opening cascade process. The noteworthy features of this strategy are highlighted by the highly efficient creation of a C(sp2)–C(sp2) bond from readily available unfunctionalized naphthols and enals catalyzed by non‐metal, readily available cyclic secondary amines under mild reaction conditions. 相似文献
18.
Lei Wu Min Shi Prof. Dr. Yuxue Li Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(17):5163-5172
BF3?OEt2‐catalyzed reactions of vinylidenecyclopropanes (VDCPs) 1 with bis(aryl)methanols 2 were thoroughly investigated. When VDCPs 1 reacted with electron‐rich bis(aryl)methanols 2 , diastereomeric rotamers of indene derivatives formed in excellent yields by a novel cationic 1,4‐aryl migration between two carbon atoms and the subsequent intramolecular Friedel–Crafts reaction pathways in the presence of BF3?OEt2 under mild conditions. As for electron‐deficient or less‐electron‐rich bis(aryl)methanols 2 , either trialkene products formed in good yields by direct deprotonation, or another type of indene derivative was produced by direct intramolecular Friedel–Crafts reaction, depending on the substituents on the cyclopropane of VDCPs. In addition, DFT calculations were carried out to explain the experimental results. Plausible mechanisms for all these transformations are proposed on the basis of the experimental and computational results. 相似文献
19.
Mixed Directing‐Group Strategy: Oxidative C−H/C−H Bond Arylation of Unactivated Arenes by Cobalt Catalysis 下载免费PDF全文
Cong Du Peng‐Xiang Li Dr. Xinju Zhu Jian‐Feng Suo Dr. Jun‐Long Niu Prof. Mao‐Ping Song 《Angewandte Chemie (International ed. in English)》2016,55(43):13571-13575
A mixed directing‐group strategy for inexpensive [Co(acac)3]‐catalyzed oxidative C?H/C?H bond arylation of unactivated arenes has been disclosed. This strategy enables the arylation of a wide range of benzamide and arylpyridines effectively to afford novel bifunctionalized biaryls, which are difficult to achieve by common synthetic routes. Two different pathways, namely, a single‐electron‐transmetalation process (8‐aminoquinoline‐directed) and a concerted metalation–deprotonation process (pyridine‐directed), were involved to activate two different inert aromatic C?H bonds. Moreover, the aryl radicals have been trapped by 2,6‐di‐tert‐butyl‐4‐methylphenol to form benzylated products. This unique strategy should be useful in the design of other arene C?H/C?H cross‐couplings as well. 相似文献
20.
Catalytic Asymmetric Reactions of 4‐Substituted Indoles with Nitroethene: A Direct Entry to Ergot Alkaloid Structures 下载免费PDF全文
Simone Romanini Emilio Galletti Dr. Lorenzo Caruana Prof. Andrea Mazzanti Prof. Fahmi Himo Dr. Stefano Santoro Prof. Mariafrancesca Fochi Prof. Luca Bernardi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(49):17578-17582
A domino Friedel–Crafts/nitro‐Michael reaction between 4‐substituted indoles and nitroethene is presented. The reaction is catalyzed by BINOL‐derived phosphoric acid catalysts, and delivers the corresponding 3,4‐ring‐fused indoles with very good results in terms of yields and diastereo‐ and enantioselectivities. The tricyclic benzo[cd]indole products bear a nitro group at the right position to serve as precursors of ergot alkaloids, as demonstrated by the formal synthesis of 6,7‐secoagroclavine from one of the adducts. DFT calculations suggest that the outcome of the reaction stems from the preferential evolution of a key nitronic acid intermediate through a nucleophilic addition pathway, rather than to the expected “quenching” through protonation. 相似文献