共查询到20条相似文献,搜索用时 72 毫秒
1.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2018,130(31):10059-10063
Functionalized indoles are recurrent motifs in bioactive natural products and pharmaceuticals. While transition metal‐catalyzed carbene transfer has provided an attractive route to afford C3‐functionalized indoles, these protocols are viable only in the presence of N‐protected indoles, owing to competition from the more facile N−H insertion reaction. Herein, a biocatalytic strategy for enabling the direct C−H functionalization of unprotected indoles is reported. Engineered variants of myoglobin provide efficient biocatalysts for this reaction, which has no precedents in the biological world, enabling the transformation of a broad range of indoles in the presence of ethyl α‐diazoacetate to give the corresponding C3‐functionalized derivatives in high conversion yields and excellent chemoselectivity. This strategy could be exploited to develop a concise chemoenzymatic route to afford the nonsteroidal anti‐inflammatory drug indomethacin. 相似文献
2.
Formal [4+2] Reaction between 1,3‐Diynes and Pyrroles: Gold(I)‐Catalyzed Indole Synthesis by Double Hydroarylation
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Yuka Matsuda Saori Naoe Dr. Shinya Oishi Prof. Dr. Nobutaka Fujii Prof. Dr. Hiroaki Ohno 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(4):1463-1467
Indole synthesis by a gold(I)‐catalyzed intermolecular formal [4+2] reaction between 1,3‐diynes and pyrroles has been developed. This reaction involves the hydroarylation of 1,3‐diynes with pyrroles followed by an intramolecular hydroarylation to give the 4,7‐disubstituted indoles. This reaction can also be applied to the synthesis of carbazoles when indoles are used as the nucleophiles instead of pyrroles. 相似文献
3.
《Journal of heterocyclic chemistry》2017,54(1):714-719
The reaction of indoles with dialdehydes was studied for the first time. Mild reaction conditions using glacial acetic acid led to two novel kinds of reaction products: one designated as alkyl chain‐connected tetraindoles and the other one as bis(indolyl)‐substituted cycloalkane indoles. The suggested reaction pathways are discussed. The indole substituents of the cycloalkane indoles were either trans or cis orientated depending from the alkyl chain length. 相似文献
4.
Kayed A. Abu Safieh Mustafa M. El‐Abadelah Musa H. Abu Zarga Salim S. Sabri Wolfgang Voelter Ccilia M. M
ssmer 《Journal of heterocyclic chemistry》2001,38(3):623-628
The synthesis of some new pyrazolo[3′,4′:6,7]azepino[5,4,3‐cd] indoles (10a‐c) was achieved via regios‐elective cyclization of the respective 3‐(4‐acylaminopyrazol‐5‐yl)indoles (9a‐c) under Bischler‐Napieralski reaction conditions. The latter compounds were obtained by acylation of the corresponding 3‐(4‐aminopyra‐zol‐5‐yl)indoles (8a,b) which, in turn, were prepared by reduction of the 3‐(4‐nitropyrazol‐5‐yl)indoles precursors (7a,b) . The latter synthons were accessible from the reaction of indolylzinc chlorides (5a,b) with 5‐chloro‐1,3‐dimethyl‐4‐nitropyrazole. Ms and nmr spectral data of 10a‐c are in agreement with the assigned azepino‐indole structure as determined for 10a by X‐ray crystal measurements which demonstrate that the azepine ring is almost completely planar with the indole and pyrazole rings. 相似文献
5.
《中国化学》2018,36(9):819-825
An iodine‐PPh3 mediated sulfenylation of indoles in water with stable and odorless sodium sulfinates as the sulfur source is described. The reaction could afford monosulfenylated indoles in moderate to excellent yields under metal free conditions. Moreover, double C—H sulfenylation of indoles at 2‐ and 3‐positions has also been achieved by using excess sodium sulfinates under the optimized reaction conditions. 相似文献
6.
Shambabu Joseph Maddirala Vidya S. Gokak Linganagouda D. Basanagoudar 《Journal of heterocyclic chemistry》2004,41(1):7-11
3‐Benzylindole‐2‐carbohydrazides (4) on reaction with triethylorthoformate in a polar solvent like DMF yielded only 10‐benzyl‐1,2‐dihydro‐1‐oxo‐1,2,4‐triazino[4,5‐a]indoles (5) while (4) on reaction with triethylorthoacetate in DMF yielded both 10‐benzyl‐4‐methyl‐1,2‐dihydro‐1‐oxo‐1,2,4‐triazino[4,5‐a]indoles (5) and 3‐benzyl‐2‐(5‐methyl‐1,3,4‐oxadiazol‐2‐yl)indoles (6) instead of only the triazinoindoles as expected. The oxadiazolylindoles (6) were also synthesized by refluxing (4) with excess of orthoesters. The structures of the compounds formed were characterized by their analytical and spectral data. 相似文献
7.
One‐Pot Sequential Propargylation/Cycloisomerization: A Facile [4+2]‐Benzannulation Approach to Carbazoles
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dr. Chada Raji Reddy Reddi Rani Valleti Uredi Dilipkumar 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(7):2501-2506
A novel one‐pot [4+2]‐benzannulation approach to substituted carbazoles is accomplished by acid‐catalyzed C3‐propargylation of 2‐alkenyl/aryl indoles with 1‐aryl propargylic alcohols, followed by cycloisomerization. A variety of 2‐alkenylated indoles and 2‐aryl/heteroaryl indoles successfully participated in this tandem reaction with 1‐aryl/heteroaryl propargylic alcohols to provide diversely substituted and annulated carbazoles, as well as an aza[5]helicene. 相似文献
8.
Gonzalo Blay Dr. Isabel Fernández Dr. M. Carmen Muñoz Prof. Dr. José R. Pedro Prof. Dr. Carlos Vila 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(30):9117-9122
Chiral complexes of BINOL‐based ligands with zirconium tert‐butoxide catalyze the Friedel–Crafts alkylation reaction of indoles with β‐trifluoromethyl‐α,β‐unsaturated ketones to give functionalized indoles with an asymmetric tertiary carbon center attached to a trifluoromethyl group. The reaction can be applied to a large number of substituted α‐trifluoromethyl enones and substituted indoles. The expected products were obtained with good yields and ees of up to 99 %. 相似文献
9.
The reaction of methyl 2‐(3‐chloro‐1,4‐dioxo‐1,4‐dihydronaphthalen‐2‐yl)propenoate ( 2a ) with primary amines gave 4‐chloro‐5‐hydroxy‐3‐methoxycarbonyl‐1H‐benzo[g]indoles 5a‐f as major compounds and 3‐methoxycarbonyl‐4,9‐dioxo‐2,3,4,9‐tetrahydro‐1H‐benzo[f]indoles 6a‐d as minor ones. Whereas the reaction of 3‐(3‐chloro‐1,4‐dioxo‐1,4‐dihydronaphthalen‐2‐yl)‐3‐buten‐2‐one ( 2b ) with primary amines afforded the corresponding 1H‐benzo[g]indoles 5g‐i as major products and 3‐acetyl‐4,9‐dihydro‐4,9‐dioxo‐1H‐benzo[f]indoles 7g, h as minor products. 相似文献
10.
Photoinduced Copper‐Catalyzed Regioselective Synthesis of Indoles: Three‐Component Coupling of Arylamines,Terminal Alkynes,and Quinones
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dr. Arunachalam Sagadevan Ayyakkannu Ragupathi Prof. Kuo Chu Hwang 《Angewandte Chemie (International ed. in English)》2015,54(47):13896-13901
The first successful example of a visible‐light‐induced copper‐catalyzed process for C? H annulation of arylamines with terminal alkynes and benzoquinone is described. This three‐component reaction allows use of a variety of commercial terminal alkynes as coupling partners for the one‐step regioselective synthesis of functionalized indoles. Moreover, the current process represents a sustainable and atom‐economical approach for the preparation of complex indoles from easily accessible starting materials under visible‐light irradiation, without the need for expensive metals and harsh reaction conditions. 相似文献
11.
Arunachalam Sagadevan Ayyakkannu Ragupathi Kuo Chu Hwang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(47):14102-14107
The first successful example of a visible‐light‐induced copper‐catalyzed process for C H annulation of arylamines with terminal alkynes and benzoquinone is described. This three‐component reaction allows use of a variety of commercial terminal alkynes as coupling partners for the one‐step regioselective synthesis of functionalized indoles. Moreover, the current process represents a sustainable and atom‐economical approach for the preparation of complex indoles from easily accessible starting materials under visible‐light irradiation, without the need for expensive metals and harsh reaction conditions. 相似文献
12.
Pd‐Catalyzed Cyclocarbonylation of 2‐(2‐Bromoaryl)indoles with CO as a C1 Source: Selective Access to 6 H‐Isoindolo[2,1‐a]indol‐6‐ones and Indeno[1,2‐b]indol‐10(5 H)‐ones
下载免费PDF全文
![点击此处可从《化学:亚洲杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A highly efficient and regioselective synthetic route to 6 H‐isoindolo[2,1‐a]indol‐6‐ones and indeno[1,2‐b]indol‐10(5 H)‐ones through the Pd‐catalyzed cyclocarbonylation of 2‐(2‐bromoaryl)indoles under atmospheric CO pressure has been achieved. Notably, the regioselectivity of the reaction was exclusively dependent on the structural characteristics of the indole substrates. With N‐unsubstituted indoles as the starting materials, the reaction afforded 6H‐isoindolo[2,1‐a]indol‐6‐ones in good‐to‐excellent yields. On the other hand, with N‐substituted indoles as the substrates, the reaction gave indeno[1,2‐b]indol‐10(5 H)‐ones in a highly regioselective manner. 相似文献
13.
Lei Peng Kai Li Chuandong Xie Shan Li Da Xu Wenling Qin Hailong Yan 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(48):17359-17364
A chiral Brønsted base catalyzed asymmetric annulation of ortho‐alkynylanilines has been developed to access axially chiral naphthyl‐C2‐indoles via vinylidene ortho‐quinone methide (VQM) intermediates. This strategy provides a unique organocatalytic atroposelective route to axially chiral aryl‐C2‐indole skeletons with excellent enantioselectivity and functional‐group tolerance. This transformation was applicable to decagram‐scale preparation (50.0 g) with perfect enantioselectivity through simple recrystallization. Moreover, the utility of this reaction was demonstrated by a variety of transformations towards chiral naphthyl‐C2‐indoles for a series of carbon–heteroatom bond formations. Furthermore, the prepared axially chiral naphthyl‐C2‐indoles were applied as a chiral skeleton for organocatalytic aza‐Baylis–Hillman reaction and asymmetric formal [4+2] tandem cyclization to give the corresponding adducts in high yields with improved enantioselectivity and diastereoselectivity. 相似文献
14.
Christle Tietcheu Christophe Garcia Daniel Gardette Denise Dugat Jean‐Claude Gramain 《Journal of heterocyclic chemistry》2002,39(5):965-973
Tricyclic keto‐indoles were synthesized by photocyclization of easily obtained enaminones in an electro‐cyclic photochemical reaction. The three methods reported were chosen according to the enaminone structure. The most general procedure using one‐step synthesis was carried out in a benzene‐methanol solution in the presence of sodium methylate. In the case of base sensitive substrates, the best method was photocyclization followed by oxidation. Besides, N‐unsubstituted indoles with a five‐membered ring were prepared by a photolysis reaction. All three methods are efficient and easy to perform. 相似文献
15.
A 4 + 2 cycloaddition reaction of NH‐free benzazetidines with indoles under the catalysis of camphorsulfonic acid was developed. This method shows a broad substrate scope of benzazetidines and indoles, and offers a convenient method for stereoselective synthesis of various cis‐2,3‐fused indoline aminals. Preliminary mechanistic studies suggest the reaction proceed via a stepwise pathway featuring an electrophilic attack on the benzylic carbon of benzazetidine. 相似文献
16.
Yu‐Hui Wang Jun‐Song Tian Peng‐Wei Tan Qiang Cao Xue‐Xin Zhang Zhong‐Yan Cao Feng Zhou Xin Wang Jian Zhou 《Angewandte Chemie (International ed. in English)》2020,59(4):1634-1643
Azacycles such as indoles and tetrahydroquinolines are privileged structures in drug development. Reported here is an unprecedented regiodivergent intramolecular nucleophilic addition reaction of imines as a flexible approach to access N‐functionalized indoles and tetrahydroquinolines, by the control of reaction at the N‐terminus and C‐terminus, respectively. Using ketimines derived from 2‐(2‐nitroethyl)anilines with isatins or α‐ketoesters, the regioselective N‐attack reaction gives N‐functionalized indoles, while the catalytic enantioselective C‐attack reaction affords chiral tetrahydroquinolines featuring an α‐tetrasubstituted stereocenter. Mechanistic studies reveal that hydrogen‐bonding interactions may greatly facilitate such unusual N‐attack reactions of imines. The utility of this protocol is highlighted by the catalytic enantioselective formal synthesis of (?)‐psychotrimine, and the construction of various fused aza‐heterocycles. 相似文献
17.
Synthesis of Novel Chiral Phosphoric Acid‐Bearing Two Acidic Phenolic Hydroxyl Groups and its Catalytic Evaluation for Enantioselective Friedel‐Crafts Alkylation of Indoles and Enones
下载免费PDF全文
![点击此处可从《Journal of heterocyclic chemistry》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Xiong‐Li Liu Zhang‐Biao Yu Bo‐Wen Pan Lin Chen Ting‐Ting Feng Ying Zhou 《Journal of heterocyclic chemistry》2015,52(2):628-634
A novel chiral phosphoric acid catalyst bearing two acidic phenolic hydroxyl groups was synthesized. Its catalytic activity as a chiral Brøsted acid has been examined in the enantioselective Friedel‐Crafts alkylation of indoles and enones as a model reaction. In comparison with the other chiral phosphoric acid catalysts, the reaction catalyzed by the novel chiral catalyst afforded the desired 3‐substituted indoles in a higher enantioselectivity (up to 69% ee). 相似文献
18.
Facile Installation of 2‐Reverse Prenyl Functionality into Indoles by a Tandem N‐Alkylation–Aza‐Cope Rearrangement Reaction and Its Application in Synthesis
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dr. Xiaobei Chen Huaqiang Fan Prof. Dr. Shilei Zhang Chenguang Yu Prof. Dr. Wei Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(2):716-723
An unprecedented tandem N‐alkylation–ionic aza‐Cope (or Claisen) rearrangement–hydrolysis reaction of readily available indolyl bromides with enamines is described. Due to the complicated nature of the two processes, an operationally simple N‐alkylation and subsequent microwave‐irradiated ionic aza‐Cope rearrangement–hydrolysis process has been uncovered. The tandem reaction serves as a powerful approach to the preparation of synthetically and biologically important, but challenging, 2‐reverse quaternary‐centered prenylated indoles with high efficiency. Notably, unusual nonaromatic 3‐methylene‐2,3‐dihydro‐1H‐indole architectures, instead of aromatic indoles, are produced. Furthermore, the aza‐Cope rearrangement reaction proceeds highly regioselectively to give the quaternary‐centered reverse prenyl functionality, which often produces a mixture of two regioisomers by reported methods. The synthetic value of the resulting nonaromatic 3‐methylene‐2,3‐dihydro‐1H‐indole architectures has been demonstrated as versatile building blocks in the efficient synthesis of structurally diverse 2‐reverse prenylated indoles, such as indolines, indole‐fused sultams and lactams, and the natural product bruceolline D. 相似文献
19.
An unprecedented palladium/copper cocatalyzed coupling reaction of indoles with simple aroyl hydrazides has been developed under aerobic conditions. A range of aroyl hydrazides underwent palladium/copper cocatalyzed oxidative arylation with indoles open to air in a 1:1 mixture of dimethyl sulfoxide and nitromethane to give structurally diverse 2‐arylindoles or 3‐arylindoles in moderate to good yields. The reaction well tolerates a wide variety of functional groups such as alkoxy, halo, ester. 相似文献
20.
Sivakolundu Bhuvaneswari Dr. Masilamani Jeganmohan Dr. Chien‐Hong Cheng Prof. Dr. 《化学:亚洲杂志》2010,5(1):141-146
N‐Methyl indole reacts with but‐2‐yn‐1‐ol in the presence of PtCl2 in MeOH giving indole derivatives having a substituted 3‐oxobutyl group at the 3‐position in good yield. Under the reaction conditions, various substituted indoles and substituted propargyl alcohols are successfully involved in the reaction giving the corresponding addition products in good to moderate yields. The catalytic reaction can be further extended to N‐phenyl pyrrole. In the present multi‐step reaction, PtCl2 likely plays dual roles: as the catalyst for the rearrangement of propargyl alcohols to the corresponding alkenyl ketones and as the catalyst for the addition of indoles to the alkenyl ketones. Experimental evidence is provided to support the proposed mechanism. 相似文献