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1.
A mild photocatalytic hydroperoxyarylation of styrenes has been developed, in which a novel photocatalyst, remazol brilliant blue R (RBBR), is employed at low catalytic loading (1 mol %). The operationally easy procedure uses air as the dioxygen source. Simple mono‐substituted styrenes react with aryl hydrazines in moderate‐to‐good yields. RBBR is proposed to act as a photosensitizer for the generation of singlet oxygen. 相似文献
2.
Hong Song Ya Li Qi‐Jun Yao Liang Jin Lei Liu Yan‐Hua Liu Bing‐Feng Shi 《Angewandte Chemie (International ed. in English)》2020,59(16):6576-6580
The atroposelective synthesis of axially chiral styrenes remains a formidable challenge due to their relatively lower rotational barriers compared to the biaryl atropoisomers. Herein, we describe the construction of axially chiral styrenes through PdII‐catalyzed atroposelective C?H olefination, using a bulky amino amide as a transient chiral auxiliary. Various axially chiral styrenes were produced with good yields and high enantioselectivity (up to 95 % yield and 99 % ee). Carboxylic acid derivatives of the resulting axially chiral styrenes showed superior enantiocontrol over the biaryl counterparts in CoIII‐catalyzed enantioselective C(sp3)?H amidation of thioamide. Mechanistic studies suggest that C?H cleavage is the enantioselectivity‐determining step. 相似文献
3.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2018,130(6):1704-1707
A method for cobalt‐catalyzed, carboxylate‐directed functionalization of arene C−H bonds is reported. Alkynes, styrenes, and 1,3‐dienes can be coupled with benzoic acids to provide cyclic products in good yields. The reactions proceed in the presence of a cobalt(II) hexafluoroacetylacetonate catalyst, (TMS)2NH base, Ce(SO4)2 cooxidant, and oxygen oxidant. 相似文献
4.
Tung Thanh Nguyen Dr. Liene Grigorjeva Prof. Dr. Olafs Daugulis 《Angewandte Chemie (International ed. in English)》2018,57(6):1688-1691
A method for cobalt‐catalyzed, carboxylate‐directed functionalization of arene C?H bonds is reported. Alkynes, styrenes, and 1,3‐dienes can be coupled with benzoic acids to provide cyclic products in good yields. The reactions proceed in the presence of a cobalt(II) hexafluoroacetylacetonate catalyst, (TMS)2NH base, Ce(SO4)2 cooxidant, and oxygen oxidant. 相似文献
5.
Yukihiro Mitsuda Takahiro Uno Masataka Kubo Takahito Itoh 《Journal of polymer science. Part A, Polymer chemistry》2005,43(21):5195-5206
Spontaneous reactions of an electron‐accepting substituted quinodimethane, 1‐(2,2‐dimethyl‐1,3‐dioxane‐4,6‐dione‐5‐ylidene)‐4‐(dicyanomethylene)‐2,5‐cyclohexadiene, with p‐substituted, α‐substituted, and β‐substituted styrenes were investigated. When p‐substituted styrenes were used as comonomers, no spontaneous reactions took place for styrenes with an electron‐accepting p substituent such as COOMe and CN groups, and both terpolymers and cycloadducts were formed for the other p‐substituted styrenes. When α‐substituted and β‐substituted styrenes were used as comonomers, no reactions occurred for α‐ and β‐substituted styrenes with a bulky phenyl group, and spontaneous reactions took place for those with a smaller methyl group. The reaction products were an alternating copolymer for α‐substituted styrene and both terpolymers and 5‐ethylidene‐2,5‐dimethyl‐1,3‐dioxane‐4,6‐dione for β‐substituted styrenes. The position of the methyl group in the styrenes significantly affected the product formation. This behavior in the spontaneous reactions was discussed on the basis of the ability of formation of the zwitterionic tetramethylene intermediate and its conformation, determined by polar and steric effects of the substituents in the substituted styrenes. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5195–5206, 2005 相似文献
6.
《合成通讯》2013,43(9):1177-1182
Abstract Bismuth(III) triflate has been found to be an efficient catalyst for the Prins reactions of styrenes and homoallyl alcohols, the reaction proceeds rapidly and affords the corresponding 1,3‐dioxanes and tetrahydropyran‐4‐ol in good yields. Scope and limitations of the styrenes and homoallyl alcohols are reported. 相似文献
7.
Copper‐Catalyzed Vicinal Diphosphination of Styrenes: Access to 1,2‐Bis(diphenylphosphino)ethane‐Type Bidentate Ligands from Olefins 下载免费PDF全文
Yuto Okugawa Prof. Dr. Koji Hirano Prof. Dr. Masahiro Miura 《Angewandte Chemie (International ed. in English)》2016,55(43):13558-13561
A copper/N‐heterocyclic carbene (NHC) catalyzed oxidative vicinal diphosphination of styrenes with diphenyl(trimethylsilyl)phosphine proceeds in the presence of LiOtBu and a pyridine N‐oxide/MnO2 combined oxidant to deliver the corresponding 1,2‐bis(diphenylphosphino)ethanes (DPPEs) in good yields. The present copper catalysis can provide access to the DPPE‐type ligands directly from the relatively simple alkenes. 相似文献
8.
《中国化学》2017,35(9):1417-1421
A novel method for the synthesis of 2‐chloro enesulfonamides via the one‐pot addition‐elimination of N ‐chloro‐N ‐fluorobenzenesulfonamides (CFBSA ) to styrenes in the presence of Et3N is described. A total of 20 examples are presented to illustrate this concept including various of styrenes. 相似文献
9.
Xihong Wang Bing Wang Xuemei Yin Wangzhi Yu Yang Liao Jialin Ye Min Wang Lianrui Hu Jian Liao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(35):12392-12398
A highly enantioselective thiocarbonylation of styrenes with CO and thiols has been achieved by Pd catalysis, providing highly enantioenriched thioesters in good to excellent yields. Key to the successful execution of this reaction is the use of a chiral sulfoxide‐(P‐dialkyl)‐phosphine (SOP) ligands. This thiocarbonylation proceeds smoothly under mild reaction conditions (1 atm CO and 0 °C) and displays broad substrate scope. Also demonstrated is that this transformation can be conducted using surrogates of CO, greatly increasing the safety aspects of running the reaction. The generality and utility of the method is manifested by its application to the synthetic transformations of thioester products and the direct acylation of cysteine‐containing dipeptides. A primary mechanism was investigated and a plausible catalytic cycle was proposed. 相似文献
10.
Yasushi Imada Yohei Okada Keiichi Noguchi Kazuhiro Chiba 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(1):131-135
Electrode materials can have a significant impact on the course of an electrolysis reaction. Of particular interest is that different electrodes can generate different products from the same substrate. The electrode‐material‐selective transformations of styrene derivatives with molecular oxygen are reported. Platinum electrodes afford carbonyl products via cleavage of olefins, whereas tetrahydrofuran formation is achieved with carbon electrodes. A variety of different styrenes are available for both reactions. Electrolysis allows straightforward and mild chemical conversions that are metal‐ and oxidant‐free. Electrochemical measurements illuminate the different effects of platinum and carbon electrodes on styrenes. The key to the differing reactions is probably that the oxidation potentials of the substrates are lower (higher HOMO energy) on carbon electrodes than on platinum electrodes. The adsorption of the substrates on carbon electrodes can also promote tetrahydrofuran formation. 相似文献
11.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(24):7000-7004
We report a formal [4+2] cycloaddition reaction of styrenes under visible‐light catalysis. Two styrene molecules with different electronic or steric properties were found to react with each other in good yield and excellent chemo‐ and regioselectivity. This reaction provides direct access to polysubstituted tetralin scaffolds from readily available styrenes. Sophisticated tricyclic and tetracyclic tetralin analogues were prepared in high yield and up to 20/1 diasteroselectivity from cyclic substrates. 相似文献
12.
A one-pot synthesis of dihydrobenzosiloles from styrenes has been developed. The reaction involves the nickel-catalyzed hydrosilylation of styrene with diphenylsilane, followed by the iridium-catalyzed dehydrogenative cyclization. This method is efficient for both electron-rich and -deficient styrenes and exhibits good functional group tolerance, as well as excellent regioselectivity. The forming dihydrobenzosiloles can be efficiently converted into valuable benzosiloles or 2-hydroxyphenethyl alcohols. 相似文献
13.
Gadde Sathish Kumar Anatoly Peshkov Aleksandra Brzozowska Pavlo Nikolaienko Chen Zhu Magnus Rueping 《Angewandte Chemie (International ed. in English)》2020,59(16):6513-6519
The first electrochemical approach for nickel‐catalyzed cross‐electrophile coupling was developed. This method provides a novel route to 1,1‐diarylalkane derivatives from simple and readily available alkyl and aryl halides in good yields and excellent regioselectivity under mild conditions. The procedure shows good tolerance for a broad variety of functional groups and both primary and secondary alkyl halides can be used. Furthermore, the reaction was successfully scaled up to the multigram scale, thus indicating potential for industrial application. Mechanistic investigation suggested the formation of a nickel hydride in the electroreductive chain‐walking arylation, which led to the development of a new nickel‐catalyzed hydroarylation of styrenes to provide a series of 1,1‐diaryl alkanes in good yields under mild reaction conditions. 相似文献
14.
A 2,6‐Bis(phenylamino)pyridinato Titanium Catalyst for the Highly Regioselective Hydroaminoalkylation of Styrenes and 1,3‐Butadienes 下载免费PDF全文
Jaika Dörfler Till Preuß Alexandra Schischko Dr. Marc Schmidtmann Prof. Dr. Sven Doye 《Angewandte Chemie (International ed. in English)》2014,53(30):7918-7922
The C? C bond forming catalytic hydroaminoalkylation of terminal alkenes, 1,3‐dienes, or styrenes allows a direct and highly atom efficient (100 %) synthesis of amines which can result in the formation of two regioisomers, the linear and the branched product. We present a new titanium catalyst with 2,6‐bis(phenylamino)pyridinato ligands for intermolecular hydroaminoalkylation reactions of styrenes and 1‐phenyl‐1,3‐butadienes that delivers the corresponding linear hydroaminoalkylation products with excellent regioselectivities. 相似文献
15.
Fengjin Wu Dr. Leifeng Wang Prof. Dr. Jiean Chen Prof. Dr. David A. Nicewicz Prof. Dr. Yong Huang 《Angewandte Chemie (International ed. in English)》2018,57(8):2174-2178
Aldehydes are among the most versatile functional groups for synthetic chemistry. However, access to polysubstituted alkyl aldehydes is very limited and requires lengthy synthetic routes that involve multiple‐step functional‐group conversion. This paper reports a one‐step synthesis of polysubstituted aldehydes from readily available olefin substrates using visible‐light photoredox catalysis. Despite a number of competing reaction pathways, commercial styrenes react with vinyl ethers selectively in the presence of an acridinium salt photooxidant and a disulfide hydrogen‐atom‐transfer catalyst under blue LED irradiation. Alkyl aldehydes with different substitution patterns are prepared in good yields. This strategy can be applied to structurally sophisticated substrates. 相似文献
16.
Shin-ichi Hirashima 《Tetrahedron letters》2009,50(30):4328-543
Carbon tetrabromide enables us to carry out oxidative cleavage of the C-C double bonds of styrenes under aerobic photo-irradiation conditions. Oxidative cleavage of the various β-substituted styrenes produced benzoic acid in good yields. Since this reaction is found to be applicable to the α- or β-substituted styrenes, which showed very low reactivity under our previous cleavage reaction condition with FSM-16 and I2, this reaction can be used complementarily. 相似文献
17.
Ana M. Sanjuán Dr. Muhammad A. Rashid Dr. Patricia García‐García Dr. Alberto Martínez‐Cuezva Dr. Manuel A. Fernández‐Rodríguez Dr. Félix Rodríguez Prof. Dr. Roberto Sanz 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(7):3042-3052
Indenes and related polycyclic structures have been efficiently synthesized by gold(I)‐catalyzed cycloisomerizations of appropriate ortho‐(alkynyl)styrenes. Disubstitution at the terminal position of the olefin was demonstrated to be essential to obtain products originating from a formal 5‐endo‐dig cyclization. Interestingly, a complete switch in the selectivity of the cyclization of o‐(alkynyl)‐α‐methylstyrenes from 6‐endo to 5‐endo was observed by adding an alcohol to the reaction media. This allowed the synthesis of interesting indenes bearing an all‐carbon quaternary center at C1. Moreover, dihydrobenzo[a]fluorenes can be obtained from substrates bearing a secondary alkyl group at the β‐position of the styrene moiety by a tandem cycloisomerization/1,2‐hydride migration process. In addition, diverse polycyclic compounds were obtained by an intramolecular gold‐catalyzed alkoxycyclization of o‐(alkynyl)styrenes bearing a nucleophile in their structure. Finally, the use of a chiral gold complex allowed access to elusive chiral 1H‐indenes in good enantioselectivities. 相似文献
18.
A catalytic amount of t-BuOK in DMSO allows the addition of ketones or imines to styrenes at 40 degrees C in good to excellent yield. Nitriles add to styrenes in NMP or in DMSO at room temperature. 相似文献
19.
NBS‐Mediated Aziridination between Styrenes and Amides under Transition Metal‐Free Conditions 下载免费PDF全文
Xu Meng Wenlin Chen Yuanqing Zhang Yongxin Chen Baohua Chen 《Journal of heterocyclic chemistry》2014,51(4):937-942
An efficient and simple protocol for N‐bromosuccinimide (NBS)‐mediated styrenes aziridination using amides as the nitrenoid source has been developed. This aziridination affords desired products in moderate to good yields without using transition metal catalyst under very mild reaction condition. 相似文献
20.
Fujiwara–Moritani Reaction of Weinreb Amides using a Ruthenium‐Catalyzed C−H Functionalization Reaction 下载免费PDF全文
The ruthenium‐catalyzed Fujiwara–Moritani reaction (oxidative‐Heck reaction) of Weinreb amides is reported herein. The reaction affords exclusively ortho‐C?H olefination products, has excellent substrate scope and tolerates halogen functionalities, which increase the synthetic utility of the method. A variety of activated olefins as well as styrenes can be employed as coupling partners. 相似文献