共查询到20条相似文献,搜索用时 20 毫秒
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Wei‐Chun Shih Chu‐Chun Teng Dr. Kanniyappan Parthasarathy Prof. Dr. Chien‐Hong Cheng 《化学:亚洲杂志》2012,7(2):306-313
A convenient method for the synthesis of highly substituted isoquinolines and isoquinolinium salts by the nickel‐catalyzed cyclization of ortho‐haloketoximes and ‐ketimines, respectively, with alkynes is described. The reaction of ortho‐haloketoximes and various alkynes in the presence of [Ni(PPh3)2Br2] and zinc powder in a mixture of acetonitrile and tetrahydrofuran at 80 °C for 15 hours gave 1,3,4‐trisubstituted isoquinoline products in moderate to excellent yields and high regioselectivity. The corresponding isoquinoline N‐oxide was found to be the intermediate in the cyclization reaction pathway. In contrast, the reaction of ortho‐haloketimines and alkynes under similar catalytic conditions in tetrahydrofuran at 70 °C for two hours gave 1,2,3,4‐tetrasubstituted isoquinolinium salts in good to excellent yields. 相似文献
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Dong Wei Meng‐Yao Li Bin‐Bin Zhu Xiao‐Di Yang Fang Zhang Chen‐Guo Feng Guo‐Qiang Lin 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(46):16695-16699
A sequential cross‐coupling/annulation of ortho‐vinyl bromobenzenes with aromatic bromides was realized, providing a direct and modular approach to access polycyclic aromatic compounds. A vinyl‐coordinated palladacycle was proposed as the key intermediate for this sequential process. Excellent chemoselectivity and regioselectivity were observed in this transformation. The practicability of this method is highlighted by its broad substrate scope, excellent functional group tolerance, and rich transformations associated with the obtained products. 相似文献
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《化学:亚洲杂志》2017,12(4):459-464
A method that allows hindered ortho ‐substituted aryl iodides to be efficiently coupled to phenylboronic acid using a gold‐catalyzed C−C bond formation is presented. The use of a molecularly‐defined dinuclear gold chloride catalytic precursor that is stabilized by a new tetradentate (N ,N′ )‐diamino‐(P,P′ )‐diphosphino ferrocene hybrid ligand in a Suzuki‐type reaction is described for the first time. Electron‐rich isopropyl groups on phosphorus were found essential for a superior activity, while the performances of a set of analogous gold dinuclear complexes that were fully characterized by multinuclear NMR spectroscopy and XRD analysis, were investigated. Therefore, arylation of para and ortho ‐substituted iodoarenes bearing electron‐rich, electron‐poor functional groups, and even hindered polycyclic aromatic compounds is described. 相似文献
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Cycloaddition reaction of 2‐aryl‐1,4‐benzoquinones 1a‐d with a number of different dienes, namely 2,3‐dimethylbutadiene; 1,4‐diphenylbutadiene and anthracene yield 2‐aryl‐6,7‐dimethyl‐1,4‐ naphthoquinones 3a,b ; 2,5,8‐triphenyl‐1,4‐naphthoquinone 4 and 2‐aryl‐1,4,9,10‐tetrahydro‐9,10‐o‐benzoanthracene‐1,4‐dione 5 , respectively were investigated. In addition, the cycloaddition reaction of 2‐aryl‐1,4‐benzoquinones 1d,e with 2,3‐dimethylbutadiene was also investigated to yield 2‐aryl‐5,8‐dihydro‐6,7‐dimethyl‐1,4‐naphthohydroquinones 2a,b . Cyclocondensation reactions of Diels‐Alder adducts 2b, 3b, 5a with ethylenediamine, o‐substituted primary aromatic amines gave quinoxaline, phenazine, phenoxazine and phenothiazine ocyclic derivatives 6–14. 相似文献
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José Vicente Prof. Dr. José‐Antonio Abad Dr. María‐José López‐Sáez Dr. Peter G. Jones Prof. Dr. Delia Bautista Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(2):661-676
Complexes [Pd(C6H3XH‐2‐R′‐5)Y(N^N)] (X=O, NH; Y=Br, I; R′=H, NO2; N^N=N,N,N′,N′‐tetramethylethylenediamine (tmeda), 2,2′‐bipyridine (bpy), 4,4′‐di‐tert‐butyl‐2,2′‐bipyridine (dtbbpy)) react with RN?C?E (E=NR, S) or RC≡N (R=alkyl, aryl, NR′′2) and TlOTf (OTf=CF3SO3) to give, respectively, 1) products of the insertion of the C?E group into the C? Pd bond, protonation of the N atom, and coordination of X to Pd, [Pd{κ2‐X,E‐(XC6H3{EC(NHR)}‐2‐R′‐4)}(N^N)]OTf or [Pd(κ2‐X,N‐{ZC6H3(NH?CR)‐2‐R′‐4})(N^N)]OTf, or products of the coordination of carbodiimides and OH addition, [Pd{κ2‐C,N‐(C6H4{OC(NR)}NHR‐2)}(bpy)]OTf; or 2) products of the insertion of the C≡N group to Pd and N‐protonation, [Pd(κ2‐X,N‐{XC6H3(NH?CR)‐2‐R′‐4})(N^N)]OTf. 相似文献
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Elias C. Rüdiger Michael Porz Manuel Schaffroth Dr. Frank Rominger Prof. Uwe H. F. Bunz 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(40):12725-12728
Two literature‐known TIPS‐ethynyl‐dibromoacenes were prepared and employed to synthesize cyclotrimers by using Yamamoto coupling conditions. Two large, well‐soluble starphenes were isolated in good yields. Crystallographic characterization verifies the triangular shape and shows significant differences in crystal packing. 相似文献
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Nicky J. Willis Dr. Christopher D. Bray 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(30):9160-9173
ortho‐Quinone methides (o‐QMs) are emerging as highly useful intermediates, the inherent reactivity of which can be used in linchpin reactions for the construction of complex natural products. This review encompasses the major contributions in this field, exemplifying the major strategies and reactivity modes which can be applied. 相似文献
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Dr. Zhongrui Chen Dr. Rose Haddoub Jérôme Mahé Dr. Gabriel Marchand Prof. Denis Jacquemin Dr. Judicaelle Andeme Edzang Dr. Gabriel Canard Dr. Daniel Ferry Dr. Olivier Grauby Alain Ranguis Dr. Olivier Siri 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(49):17820-17832
Pre‐ and postintroduction of substituents with respect to the macrocyclization step leads to previously unknown N‐substituted azacalixphyrins. The stepwise synthetic approach has been studied in detail to highlight the key role of the N‐substituents of the precursors and/or intermediates in terms of reactivity. Based on a combined experimental and theoretical investigation, the relationship between the properties of the macrocycles and their degree of substitution is rationalized. Depending on the nature of the N‐substituents, the formation of supramolecular ribbon‐like structures could also be observed, as demonstrated by combined TEM, SEM, AFM, and FTIR experiments. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(43):13655-13659
The regioselective transformation of heterobuckybowl trichalcogenasumanenes 1 a , b at peripheral butoxy groups afforded trichalcogenasumanene ortho ‐quinones 2 a , b . Compounds 2 a , b are distinct from 1 a , b in terms of their molecular geometry and electronic state; that is, they have a shallower bowl depth and show absorbance in the NIR region. The reaction of 2 a , b with diamines resulted in a variety of heteropolycycles, including molecular spoon 3 a – 6 a , planar π‐systems 3 b – 6 b , and highly twisted [7‐6‐6]‐fused systems 7 a , b . These new heteropolycycles had different optical/electrical properties: 4 a,b showed hole mobility of approximately 0.002 cm2 V−1 s−1, 6 a displayed red emission in both solution and the solid state, and 7 a , b formed tight stacks of the curved π‐surface. 相似文献
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《Angewandte Chemie (International ed. in English)》2017,56(43):13470-13474
The regioselective transformation of heterobuckybowl trichalcogenasumanenes 1 a , b at peripheral butoxy groups afforded trichalcogenasumanene ortho ‐quinones 2 a , b . Compounds 2 a , b are distinct from 1 a , b in terms of their molecular geometry and electronic state; that is, they have a shallower bowl depth and show absorbance in the NIR region. The reaction of 2 a , b with diamines resulted in a variety of heteropolycycles, including molecular spoon 3 a – 6 a , planar π‐systems 3 b – 6 b , and highly twisted [7‐6‐6]‐fused systems 7 a , b . These new heteropolycycles had different optical/electrical properties: 4 a,b showed hole mobility of approximately 0.002 cm2 V−1 s−1, 6 a displayed red emission in both solution and the solid state, and 7 a , b formed tight stacks of the curved π‐surface. 相似文献
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Hydroamination Reactions of Alkynes with ortho‐Substituted Anilines in Ball Mills: Synthesis of Benzannulated N‐Heterocycles by a Cascade Reaction 下载免费PDF全文
Maik Weiße Markus Zille Katharina Jacob Robert Schmidt Achim Stolle 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(17):6511-6522
It was demonstrated that ortho‐substituted anilines are prone to undergo hydroamination reactions with diethyl acetylenedicarboxylate in a planetary ball mill. A sequential coupling of the intermolecular hydroamination reaction with intramolecular ring closure was utilized for the syntheses of benzooxazines, quinoxalines, and benzothiazines from readily available building blocks, that is, electrophilic alkynes and anilines with OH, NH, or SH groups in the ortho position. For the heterocycle formation, it was shown that several stress conditions were able to initiate the reaction in the solid state. Processing in a ball mill seemed to be advantageous over comminution with mortar and pestle with respect to process control. In the latter case, significant postreaction modification occurred during solid‐state analysis. Cryogenic milling proved to have an adverse effect on the molecular transformation of the reagents. 相似文献
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Shao‐Tao Bai Charles B. Bheeter Joost N. H. Reek 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(37):13173-13177
Reported is an iridium catalyst for ortho‐selective C?H borylation of challenging secondary aromatic amide substrates, and the regioselectivity is controlled by hydrogen‐bond interactions. The BAIPy ‐Ir catalyst forms three hydrogen bonds with the substrate during the crucial activation step, and allows ortho‐C?H borylation with high selectivity. The catalyst displays unprecedented ortho selectivities for a wide variety of substrates that differ in electronic and steric properties, and the catalyst tolerates various functional groups. The regioselective C?H borylation catalyst is readily accessible and converts substrates on gram scale with high selectivity and conversion. 相似文献