共查询到20条相似文献,搜索用时 31 毫秒
1.
Nazli Jalalian Dr. Tue B. Petersen Prof. Berit Olofsson 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(44):14140-14149
Phenols and carboxylic acids are efficiently arylated with diaryliodonium salts. The reaction conditions are mild, metal free, and avoid the use of halogenated solvents, additives, and excess reagents. The products are obtained in good‐to‐excellent yields after short reaction times. Steric hindrance is very well tolerated, both in the nucleophile and diaryliodonium salt. The scope includes ortho‐ and halo‐substituted products, which are difficult to obtain by metal‐catalyzed protocols. Many functional groups are tolerated, including carbonyl groups, heteroatoms, and alkenes. Unsymmetric salts can be chemoselectively utilized to obtain products with hitherto unreported levels of steric congestion. The arylation has been extended to sulfonic acids, which can be converted to sulfonate esters by two different approaches. With recent advances in efficient synthetic procedures for diaryliodonium salts the reagents are now inexpensive and readily available. The iodoarene byproduct formed from the iodonium reagent can be recovered quantitatively and used to regenerate the diaryliodonium salt, which improves the atom economy. 相似文献
2.
Zsombor Gonda Dr. Zoltán Novák 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(47):16801-16806
A new synthetic method was developed for the N‐arylation of pyrazoles using diaryliodonium salts. The transformation does not require any transition‐metal catalyst and provides the desired N‐arylpyrazoles rapidly under mild reaction condition in the presence of aqueous ammonia solution as a mild base without the use of inert atmosphere. The chemoselectivity of unsymmetric diaryliodonium salts was also explored with large number of examples. 相似文献
3.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(19):5347-5350
Both aryl components of diaryliodonium salts can be used in a domino one‐pot reaction via in situ generation of a directing group. A number of heterocycles undergo N‐arylation which is followed by ruthenium‐catalyzed C‐arylation. Notably the reaction extends well to unsymmetrical diaryliodonium salts with a number of highly selective examples shown. 相似文献
4.
James V. Crivello Michael F. Aldersley 《Journal of polymer science. Part A, Polymer chemistry》2013,51(4):801-814
Diaryliodonium salts spontaneously form crystalline 1:1 supramolecular complexes at room temperature in good to excellent yields with 18‐crown‐6 ether and its cyclohexano‐ and benzo‐substituted analogs. The complexes were characterized using IR, UV, MS, 1H, and 13C‐NMR spectroscopy and by single crystal X‐ray crystallography. The analytical data obtained were consistent with a structure in which the positively charged iodine atom of diaryliodonium cation is positioned above and over the center of the crown ether ring with the positively charged iodine atom coordinated to the crown ether oxygen atoms. The diaryliodonium salt‐crown ether complexes are photosensitive and were used to carry out the photoinitiated cationic polymerizations of a number of mono‐ and difunctional monomers. During irradiation with UV light, the supramolecular complexes undergo photolysis with the generation of a Brønsted acid and with the concomitant release of the crown ether. When used as photoinitiators, the crown ether that is released markedly influences the kinetics of the subsequent cationic polymerization of the monomer. Further studies demonstrated that the photolysis of diaryliodonium salt‐crown ether supramolecular complexes can be photosensitized using typical‐electron transfer photosensitizers. Free radical‐promoted photosensitization using typical unimolecular free radical photoinitiators such as 2,2‐dimethoxy‐2‐phenylacetophenone also takes place readily. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 相似文献
5.
Igor L. Zheldakov Oleg Grinevich Alexander Mejiritski Christopher G. Elles Douglas C. Neckers 《Photochemistry and photobiology》2014,90(2):335-337
DIBF (5,7‐diiodo‐3‐butoxy‐6‐fluorone) is a visible light photosensitizer for diaryliodonium salts, the latter being used in cationic photopolymerizations. Although photopolymerization of cycloaliphatic epoxide resins can be initiated by direct excitation of UV‐absorbing diaryliodonium salts, such as (p‐octyloxy)phenyliodonium hexafluoroantimonate (OPPI), the short wavelengths required cause some practical problems. Sensitizers, of which DIBF is among the best, obviate the deep UV problem by allowing visible‐wavelength activation of the photoinitiator. Addition of 9,10‐diethoxyanthracene (AN 910 E) dramatically accelerates photopolymerization under visible irradiation of the DIBF/OPPI system. We report herein the transient spectroscopy of the photosensitizer DIBF and discuss likely mechanisms for sensitization of OPPI. 相似文献
6.
The photo‐initiated cationic polymerization (PCP) of epoxides using diaryliodonium salt photoacid generators (PAGs) bearing alkyl groups and anions was investigated. The properties and reactivities of a series of iodonium salts containing various cations and anions were compared in the context of a PCP reaction. The products from the decomposition of the cations of these salts were analyzed using gas chromatography‐mass spectrometry (GC‐MS) spectra. The relationship between the molecular structure of the salts and their reaction mechanism in the PCP reaction was investigated. Based on the results of the investigation, it was concluded that the structures of the cations and anions of theiodonium salts affect the PCP reaction rate, which was controlled by the products from the diaryliodonium salts. As part of an additional investigation, the diaryliodonium salts‐epoxide materials were applied to 254 nm‐photo‐patterning. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
7.
A Metal‐free Approach to 3‐Aryl‐3‐hydroxy‐2‐oxindoles by Treatment of 3‐Acyloxy‐2‐oxindoles with Diaryliodonium Salts
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 mild, metal‐free approach has been realized for the facile construction of highly valuable 3‐(hetero)aryl‐3‐hydroxy‐2‐oxindoles. Direct arylations of 3‐acyloxy‐2‐oxindoles with diaryliodonium salts as arylation reagents are implemented in the presence of K2CO3 at room temperature without using an organometallic promoter to deliver an array of 3‐(hetero)aryl‐3‐hydroxy‐2‐oxindoles in good yields. 相似文献
8.
Ruixian Deng Shuming Zhan Chunyu Li Zhenhua Gu 《Angewandte Chemie (International ed. in English)》2020,59(8):3093-3098
A transition‐metal‐free synthesis of spiro compounds from 9H‐fluoren‐9‐ols mediated by hypervalent iodine is reported. In this reaction, an unprecedented β‐carbon elimination of tertiary alkoxyliodine(III) to form new diaryliodonium salts is proposed. The obtained phenol intermediates undergo oxidative dearomatization to furnish a class of oxo‐spiro compounds. This domino reaction significantly increases the complexity of these molecules and shows excellent regio‐ and stereoselectivity. 相似文献
9.
C‐2 Selective Arylation of Indoles with Heterogeneous Nanopalladium and Diaryliodonium Salts
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)
Joel Malmgren Anuja Nagendiran Dr. Cheuk‐Wai Tai Prof. Jan‐E. Bäckvall Prof. Berit Olofsson 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(42):13531-13535
A simple and efficient method to prepare synthetically useful 2‐arylindoles is presented, using a heterogeneous Pd catalyst and diaryliodonium salts in water under mild conditions. A remarkably low leaching of metal catalyst was observed under the applied conditions. The developed protocol is highly C‐2 selective and tolerates structural variations both in the indole and in the diaryliodonium salt. Arylations of both N?H indoles and N‐protected indoles with ortho‐substituted, electron‐rich, electron‐deficient, or halogenated diaryliodonium salts were achieved to give the desired products in high to excellent isolated yields within 6 to 15 h at room temperature or 40 °C. 相似文献
10.
Conversion of 2‐Iodobiaryls into 2,2′‐Diiodobiaryls via Oxidation‐Iodination Sequences: A Versatile Route to Ladder‐Type Heterofluorenes
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)
Bin Wu Prof. Naohiko Yoshikai 《Angewandte Chemie (International ed. in English)》2015,54(30):8736-8739
Even though 2,2′‐diiodo‐ and 2,2′‐dibromobiaryls represent accomplished precursors for heterofluorenes and other extended π‐conjugated systems, their preparation still remains nontrivial when structural diversity of the biaryl backbone is required. Herein, we report a convenient method for the preparation of various 2,2′‐diiodobiaryls from 2‐iodobiaryls via cyclic diaryliodonium intermediates. An iodinative ring‐opening of the diaryliodonium salts, mediated by a copper/diamine catalyst system, is able to afford the corresponding 2,2′‐diiodobiaryls under mild conditions. The versatility of this two‐step approach is demonstrated by the preparation of hitherto unexplored tetraiodoteraryls and their conversion into ladder‐type π‐conjugated systems. 相似文献
11.
Nobutaka Yamaoka Kohei Sumida Itsuki Itani Hiroko Kubo Yusuke Ohnishi Sho Sekiguchi Dr. Toshifumi Dohi Prof. Dr. Yasuyuki Kita 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(44):15004-15011
Metal‐free oxidative C? C coupling by using polyalkoxybenzene‐derived diaryliodonium(III) salts as both the oxidant and aryl source has been developed. These salts can induce single‐electron‐transfer (SET) oxidation to yield electron‐rich arenes and subsequently transfer the polyalkoxyphenyl group into in situ generated aromatic radical cations to produce biaryl products. The reaction is promoted by a Lewis acid that activates the iodonium salts. It has been revealed that the reactivity of the salts under acidic conditions is quite different to their known behavior under basic conditions. The reactivity preference of a series of iodonium salts in the SET oxidation and their ligand transfer abilities have been systematically investigated and the results are summarized in this report. 相似文献
12.
Through‐Space 1,4‐Palladium Migration and 1,2‐Aryl Shift: Direct Access to Dibenzo[a,c]carbazoles through a Triple CH Functionalization Cascade
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)
Samir Kumar Bhunia Arghya Polley Dr. Ramalingam Natarajan Dr. Ranjan Jana 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(47):16786-16791
A palladium‐catalyzed expeditious synthesis of dibenzofused carbazoles from readily available 2‐arylindoles and diaryliodonium salts is reported. Interestingly, after the electrophilic C3 palladation of indole, an unexpected “through‐space” 1,4‐palladium migration to the 2‐aryl moiety, by remote C?H bond activation followed by C?H arylation with diaryliodonium salt, and an unprecedented 1,2‐aryl shift take place. Finally, an intramolecular cross‐dehydrogenative coupling (CDC) at the C2 position affords dibenzo[a,c]carbazoles in high yields. Remarkably, the present migratory annulation occurs through three C?H bond activation one C?C bond cleavage, and the simultaneous construction of three new C?C bonds in a single operation. 相似文献
13.
Copper‐Catalyzed Enantioselective Arylative Desymmetrization of Prochiral Cyclopentenes with Diaryliodonium Salts
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. Hua Wu Dr. Qian Wang Prof. Dr. Jieping Zhu 《Angewandte Chemie (International ed. in English)》2018,57(10):2721-2725
A copper‐catalyzed enantioselective arylative desymmetrization of prochiral cyclopentenes with diaryliodonium salts was developed. In the presence of a catalytic amount of a chiral copper–bisoxazoline complex, which was generated in situ, the reaction of 4‐substituted or 4,4‐disubstituted cyclopent‐1‐enes with diaryliodonium hexafluoroarsenates afforded the chiral arylated products in good yields with excellent enantioselectivity. A cyclohexyl‐containing Box ligand was essential for the high enantioselectivity. Transformation of the enantiomerically enriched adducts into other chiral building blocks is also documented. 相似文献
14.
Base‐Promoted Coupling of Carbon Dioxide,Amines, and Diaryliodonium Salts: A Phosgene‐ and Metal‐Free Route to O‐Aryl Carbamates
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)
Wenfang Xiong Dr. Chaorong Qi Youbin Peng Tianzuo Guo Prof. Dr. Min Zhang Prof. Dr. Huanfeng Jiang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(41):14314-14318
A phosgene‐ and metal‐free synthesis of O‐aryl carbamates is realized through a three‐component coupling of carbon dioxide, amines and diaryliodonium salts. The reaction only requires a base as the promoter, providing access to a diverse array of O‐aryl carbamates in moderate to high yields with excellent chemoselectivity. 相似文献
15.
Regiospecific N‐Arylation of Aliphatic Amines under Mild and Metal‐Free Reaction Conditions
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. Nibadita Purkait Gabriella Kervefors Erika Linde Prof. Berit Olofsson 《Angewandte Chemie (International ed. in English)》2018,57(35):11427-11431
A transition metal‐free N‐arylation of primary and secondary amines with diaryliodonium salts is presented. Both acyclic and cyclic amines are well tolerated, providing a large set of N‐alkyl anilines. The methodology is unprecedented among metal‐free methods in terms of amine scope, the ability to transfer both electron‐withdrawing and electron‐donating aryl groups, and efficient use of resources, as excess substrate or reagents are not required. 相似文献
16.
Gang Wang Biquan Xiong Congshan Zhou Yu Liu Weifeng Xu Chang‐An Yang Ke‐Wen Tang Wai‐Yeung Wong 《化学:亚洲杂志》2019,14(23):4365-4374
A copper‐catalyzed diphenylation of P(O)?OH bonds with cyclic diaryliodonium salts is described. Valuable 2′‐iodo substituted biaryl phosphinic/phosphoric acid esters were obtained in good to excellent yields, which could be further transformed to diversified building blocks for the synthesis of bioactive compounds, pharmaceuticals and functional materials. 相似文献
17.
Tosylhydrazones are a kind of labile and highly reactive compounds, which are apt to be transformed into reactive diazo compounds and then into extremely reactive carbenes under the basic condition. In order to fulfil the valuable C‐N coupling reaction, diaryliodonium salts are evaluated and prove to be a class of efficient electrophiles. The reaction with ligand‐free copper salt as catalyst shows a wide range of substrate scope. A plausible mechanism is proposed. 相似文献
18.
James V. Crivello Julia L. Lee 《Journal of polymer science. Part A, Polymer chemistry》2010,48(20):4484-4495
In this article, a new route for the synthesis of N‐aryl heteroaromatic onium salts by the direct copper catalyzed arylation of pyridine, substituted pyridines, isoquinoline, and acridine with diaryliodonium salts is described. It was demonstrated that these N‐aryl heteroaromatic onium salts undergo facile platinum or rhodium‐catalyzed reduction by silanes bearing Si? H groups. The reduction of N‐aryl heteroaromatic onium salts generates Brønsted acids. When this redox reaction was carried out in situ in the presence of an appropriate monomer, cationic polymerization was observed. Using this approach, the cationic polymerizations of epoxides, oxetanes, 1,3,5‐trioxane, styrene, and vinyl ethers were carried out. The use of optical pyrometry to monitor the redox initiated cationic polymerizations of some representative multifunctional monomers is described. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献
19.
One‐pot Annulation for Biaryl‐fused Monocarba‐closo‐dodecaborate through Aromatic B−H Bond Disconnection
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)
Gaku Akimoto Mai Otsuka Dr. Kazunori Miyamoto Dr. Atsuya Muranaka Dr. Daisuke Hashizume Dr. Ryo Takita Prof. Dr. Masanobu Uchiyama 《化学:亚洲杂志》2018,13(8):913-917
We have developed a one‐pot annulation reaction of monocarba‐closo‐dodecaborate with cyclic diaryliodonium salts to afford biaryl‐fused derivatives. Aryl functionalities are introduced at both the 1‐carbon and unreactive ortho‐boron vertices of the “σ‐aromatic” carborane cage without the need for pre‐functionalization. DFT calculations revealed that the palladium‐catalyzed C?B bond‐formation step in this process proceeds through a concerted metalation–deprotonation (CMD)‐type pathway for the B?H bond disconnection on the aromatic cage, though such bonds are generally regarded as hydridic. 相似文献
20.
N‐arylbenzimidazoles were prepared in moderate yields by copper‐catalyzed N‐arylation of benzimidazole with diaryliodonium salts. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:617–619, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10043 相似文献