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1.
Dr. Wei‐Wu Ren Zhi‐Xing Chen Dr. Qing Xiao Yong Li Tian‐Wen Sun Zi‐Yang Zhang Qin‐Da Ye Fan‐Ke Meng Lin You Ming‐Zhe Zhao Ling‐Min Xu Prof. Dr. Ye‐Feng Tang Prof. Dr. Jia‐Hua Chen Prof. Dr. Zhen Yang 《化学:亚洲杂志》2012,7(10):2341-2350
The final phase for the total synthesis of (±)‐schindilactone A ( 1 ) is described herein. Two independent synthetic approaches were developed that featured Pd–thiourea‐catalyzed cascade carbonylative annulation reactions to construct intermediate 3 and a RCM reaction to make intermediate 4 . Other important steps that enabled the completion of the synthesis included: 1) A Ag‐mediated ring‐expansion reaction to form vinyl bromide 17 from dibromocyclopropane 30 ; 2) a Pd‐catalyzed coupling reaction of vinyl bromide 17 with a copper enolate to synthesize ketoester 16 ; 3) a RCM reaction to generate oxabicyclononenol 10 from diene 11 ; 4) a cyclopentenone fragment in substrate 8 was constructed through a Co–thiourea‐catalyzed Pauson–Khand reaction (PKR); 5) a Dieckmann‐type condensation to successfully form the A ring of schindilactone A ( 1 ). The chemistry developed for the total synthesis of schindilactone A ( 1 ) will shed light on the synthesis of other family members of schindilactone A. 相似文献
2.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(40):12254-12259
We introduce a novel application of an oscillatory chemical reaction to the synthesis of block copolymers. The Belousov–Zhabotinsky (B‐Z) reaction is coupled with the polymerization of an amphiphilic block copolymer. Radicals generated in the B‐Z reaction initiate the polymerization between a polyethylene glycol (PEG) macroreversible addition‐fragmentation chain‐transfer agent and butyl acrylate monomers. The attachment of a hydrophobic block on PEG leads to self‐assembly and formation of spherical micelles. The nanoscale micelles transform into submicrometer vesicles and grow to giant vesicles as a consequence of the oscillatory behavior of the B‐Z reaction. The one‐pot synthesis of an amphiphilic di‐block copolymer and retention of oscillatory behavior for the B‐Z reaction with the formation of giant vesicles bring a new insight into possible pathways for the synthesis of active functional microreactors in the range from hundreds of nanometers to tens of micrometers. 相似文献
3.
Tandem Allylboration–Prins Reaction for the Rapid Construction of Substituted Tetrahydropyrans: Application to the Total Synthesis of (−)‐Clavosolide A 下载免费PDF全文
Dr. Alba Millán James R. Smith Jack L.‐Y. Chen Prof. Dr. Varinder K. Aggarwal 《Angewandte Chemie (International ed. in English)》2016,55(7):2498-2502
Tetrahydropyrans are common motifs in natural products and have now been constructed with high stereocontrol through a three‐component allylboration‐Prins reaction sequence. This methodology has been applied to a concise (13 steps) and efficient (14 % overall yield) synthesis of the macrolide (?)‐clavosolide A. The synthesis also features an early stage glycosidation reaction to introduce the xylose moiety and a lithiation‐borylation reaction to attach the cyclopropyl‐containing side chain. 相似文献
4.
Yusuke Iwama Dr. Kentaro Okano Dr. Kenji Sugimoto Prof. Dr. Hidetoshi Tokuyama 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(28):9325-9334
A racemic synthesis of mersicarpine ( 1 ) was achieved by the Mizoroki–Heck reaction and a DIBALH‐mediated reductive ring‐expansion reaction. Based on a first‐generation synthesis, a second‐generation enantiocontrolled total synthesis of (?)‐mersicarpine ( 1 ) was achieved by an 8‐pot/11‐step sequence in 21 % overall yield from commercially available 2‐ethylcyclohexanone. Subjection of a ketoester, which was prepared by an asymmetric Michael addition (according to the protocol by d’Angelo and Desmaële), and phenylhydrazine to modified Fischer indole conditions provided a six‐membered tricyclic indole. Benzylic oxidation and subsequent oxime formation provided a ketoxime, which was treated with diisobutylaluminum hydride (DIBALH) to construct the characteristic azepinoindole skeleton in good yield. In the DIBALH‐mediated reductive ring‐expansion reaction, gradually increasing the reaction temperature and in situ‐protection of the nitrogen in an oxygen‐sensitive azepinoindole with a benzyloxycarbonyl (Cbz) group were crucial for the high‐yielding process. With these methodologies, the short‐step and efficient synthesis of (?)‐mersicarpine was accomplished. Several synthetic efforts are also described. 相似文献
5.
Asymmetric Disulfonimide‐Catalyzed Synthesis of δ‐Amino‐β‐Ketoester Derivatives by Vinylogous Mukaiyama–Mannich Reactions 下载免费PDF全文
Dr. Qinggang Wang Manuel van Gemmeren Prof. Dr. Benjamin List 《Angewandte Chemie (International ed. in English)》2014,53(49):13592-13595
An organocatalytic asymmetric synthesis of δ‐amino‐β‐ketoester derivatives has been developed. A chiral disulfonimide (DSI) serves as a highly efficient precatalyst for a vinylogous Mukaiyama–Mannich reaction of readily available dioxinone‐derived silyloxydienes with N‐Boc‐protected imines, delivering products in excellent yields and enantioselectivities. The synthetic utility of this reaction is illustrated in various transformations, including a new C? C bond‐forming reaction, which provide useful enantioenriched building blocks. The methodology is applied in a formal synthesis of (?)‐lasubin. 相似文献
6.
《Journal of heterocyclic chemistry》2017,54(1):660-669
In the current study, divers pyrimidine‐fused heterocycles containing an imidazole, benzimidazole, or theophylline moieties were synthesized. For the synthesis of this category of compounds, first, some new bromo‐substituted aldehydes (BSAs) were synthesized using reaction of 4‐hydroxybenzaldehyde and dibromides. Then, BSAs were reacted with imidazole, benzimidazole, and theophylline in order to synthesize corresponding heterocyclic‐substituted aldehydes (HSAs). Finally, the synthesized HSAs underwent in a multi‐components reaction with barbituric acids, amines, and dimedone in the presence of magnetic nanoparticles‐supported tungstic acid (MNP‐TA) catalyst in order to synthesis target products in good to excellent yields. The MNP‐TA was reusable using an external magnetic field and providing a clean and efficient reaction conditions for efficient synthesis of this class of compounds. 相似文献
7.
An Efficient Synthesis of Benzazocines by Gold(I)‐Catalyzed Tandem 1,2‐Acyloxy Shift/[3+2] Cycloaddition of Terminal 1,9‐Enynyl Esters 下载免费PDF全文
Shangbiao Feng Zhengshen Wang Weiwei Zhang Prof. Dr. Xingang Xie Prof. Dr. Xuegong She 《化学:亚洲杂志》2016,11(15):2167-2172
An effective synthesis of structurally diverse benzazocines was accomplished in good to excellent chemical yields (55–82 %) through a gold(I)‐catalyzed cascade reaction involving tandem 1,2‐acyloxy shift/[3+2] cycloaddition of terminal 1,9‐enynyl esters. The reaction proceeds under extremely mild conditions and represents one of the relatively few transition‐metal‐catalyzed intramolecular cycloaddition reactions for the synthesis of benzazocines. 相似文献
8.
Dimethyl acetylenedicarboxylate (DMAD) is a very important and useful reagent for the preparation of dimethyl heterocyclic‐o‐dicarboxylates, which are key intermediates in the synthesis of fused pyridazine derivatives. The synthesis of thiopyranes by the Diels‐Alder reaction of dithiocarboxylate derivatives, synthesis of various cyclazines by [2 + 8] cycloaddition reactions, and synthesis of dimethyl pyrazolo[3,4‐b]pyridine‐5,6‐dicarboxylates and polycyclic heterocycles containing the 1,6‐naphthyridine ring system by the reaction of o‐aminonitrile compounds with DMAD are described here. 相似文献
9.
Microwave and Ultrasound‐Assisted Synthesis of Thiosemicarbazones and Their Corresponding (4,5‐Substituted‐thiazol‐2‐yl)hydrazines 下载免费PDF全文
Simone Carradori Daniela Secci Melissa D'Ascenzio Paola Chimenti Adriana Bolasco 《Journal of heterocyclic chemistry》2014,51(6):1856-1861
Hantzsch cyclization of thiosemicarbazone intermediates is a very popular approach to the synthesis of substituted thiazoles. We developed a convenient microwave and ultrasound‐assisted method both for the synthesis of 1‐(alkyliden/cycloalkyliden/aryliden)thiosemicarbazone intermediates and their cyclization into (4,5‐substituted‐thiazol‐2‐yl)hydrazines. The search for optimal reaction conditions included the use of different catalysts (Lewis acids and resins) and solvents at discrete temperatures, pressures, and irradiation powers. Comparing yields, reaction times, and efforts proved that microwave and ultrasound‐assisted techniques outmatch conventional heating and have a remarkable influence on the synthesis. 相似文献
10.
Qianqian Zhen Lepeng Chen Linjun Qi Kun Hu Yinlin Shao Renhao Li Jiuxi Chen 《化学:亚洲杂志》2020,15(1):106-111
The first example of the nickel‐catalyzed tandem addition/cyclization of 2‐(cyanomethyl)benzonitriles with arylboronic acids in 2‐MeTHF has been developed, which provides the facile synthesis of aminoisoquinolines with good functional group tolerance under mild conditions. This chemistry has also been successfully applied to the synthesis of isoquinolones by the tandem reaction of methyl 2‐(cyanomethyl)benzoates with arylboronic acids. The use of the bio‐based and green solvent 2‐MeTHF as the reaction medium makes the synthesis process environmentally benign. The synthetic utility of this chemistry is also indicated by the synthesis of biologically active molecules. 相似文献
11.
Copper‐Catalyzed Domino Synthesis of 2‐Imino‐1H‐imidazol‐5(2H)‐ones and Quinoxalines Involving CC Bond Cleavage with a 1,3‐Dicarbonyl Unit as a Leaving Group 下载免费PDF全文
Yan Yang Fan Ni Wen‐Ming Shu Prof. An‐Xin Wu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(37):11776-11782
Although 2‐imino‐1H‐imidazol‐5(2H)‐ones have important biological activities in metabolism, their synthesis has rarely been investigated. Quinoxalines as “privileged scaffolds” in medicinal chemistry have been extensively investigated, but the development of novel and efficient synthetic methods remains very attractive. Herein, we have developed two copper‐catalyzed domino reactions for the synthesis of 2‐imino‐1H‐imidazol‐5(2H)‐ones and quinoxalines involving C?C bond‐cleavage with a 1,3‐dicarbonyl unit as a leaving group. The domino sequence for the synthesis of 2‐imino‐1H‐imidazol‐5(2H)‐ones includes aza‐Michael addition, intramolecular cyclization, C?C bond‐cleavage, 1,2‐rearrangement, and aerobic dehydrogenation reaction, whereas the domino sequence for the synthesis of quinoxalines includes aza‐Michael addition, intramolecular cyclization, elimination reaction, and C?C bond‐cleavage reaction. The two domino reactions have significant advantages including high efficiency, mild reaction conditions, and high tolerance of various functional groups. 相似文献
12.
Construction of a Hemifullerene Skeleton: A Regioselective Intramolecular Oxidative Cyclization 下载免费PDF全文
Dr. Toru Amaya Takanori Ito Prof. Dr. Toshikazu Hirao 《Angewandte Chemie (International ed. in English)》2015,54(18):5483-5487
A two‐step synthesis of a strained π bowl, with hemifullerene skeleton from sumanene, was achieved in a high yield. The first step is a base‐promoted condensation reaction with a benzophenone compound, bis(3,5‐dimethylphenyl)methanone. The second step is the regioselective intramolecular oxidative cyclization, which is a key reaction for the hemifullerene skeleton synthesis. This regioselective cyclization is likely to be under thermodynamic control. This strategy will allow facile synthesis of various highly strained π bowls. 相似文献
13.
Taichi Kurogi Shun Okaya Dr. Hideto Fujiwara Dr. Kentaro Okano Prof. Dr. Hidetoshi Tokuyama 《Angewandte Chemie (International ed. in English)》2016,55(1):283-287
The first total synthesis of an epidithiodiketopiperazine alkaloid, (+)‐MPC1001B, was accomplished. This synthesis features a tetra‐n‐butylammonium fluoride mediated intramolecular aldol reaction for forming the 15‐membered macrolactone ring, and the construction of an epidithiodiketopiperazine substructure through a stepwise sulfenylation reaction involving a novel trityl trisulfide (TrSSS)‐group transfer. 相似文献
14.
Prof. Dr. J. Stephen Clark Dr. Chao Xu 《Angewandte Chemie (International ed. in English)》2016,55(13):4332-4335
A highly efficient 12‐step synthesis of the marine alkaloid (?)‐nakadomarin A has been accomplished. The key advanced intermediate, a tetracyclic ketone derivative, was constructed in just seven steps using a sequence that includes an asymmetric Pauson–Khand reaction, an Overman rearrangement reaction, a ring‐closing metathesis reaction, and an amination reaction. Late introduction of the furan ring during the synthesis of (?)‐nakadomarin A means that the key tetracyclic ketone derivative has the potential to serve as an advanced intermediate for the synthesis of related marine alkaloids. 相似文献
15.
Preparation of Furo[3,2‐c]coumarins from 3‐Cinnamoyl‐4‐hydroxy‐2H‐chromen‐2‐ones and Acyl Chlorides: A Bu3P‐Mediated C‐Acylation/Cyclization Sequence 下载免费PDF全文
Chia‐Jui Lee Cheng‐Che Tsai Shao‐Hao Hong Geng‐Hua Chang Mei‐Chun Yang Dr. Lennart Möhlmann Prof. Dr. Wenwei Lin 《Angewandte Chemie (International ed. in English)》2015,54(29):8502-8505
A Bu3P‐mediated cyclization reaction of 3‐cinnamoyl‐4‐hydroxy‐2H‐chromen‐2‐ones though electrophilic addition of acyl chlorides towards the synthesis of highly functionalized furo[3,2‐c]coumarins bearing a phosphorus ylide moiety is described. These unprecedented cyclization reaction proceeds under mild reaction conditions within short reaction times (1 min to 1 h), and can be further applied in the synthesis of alkenyl‐substituted furo[3,2‐c]coumarins by the treatment with carbonyl electrophiles under basic conditions. 相似文献
16.
Total enantioselective synthesis of the natural (‐)‐Herbertenediol (1) was accomplished in eleven steps with an overall yield of 15% starting from the 2‐methoxy‐4‐methyl‐phenol. The total synthesis features asymmetric intramolecular Heck reaction and Wolff‐Kishner‐Huang reduction. (aR, aS)‐Mastigophorenes A was also synthesized through the oxidative coupling reaction. 相似文献
17.
Ruthenium‐Catalyzed Multicomponent Reactions: Access to α‐Silyl‐β‐Hydroxy Vinylsilanes,Stereodefined 1,3‐Dienes,and Cyclohexenes 下载免费PDF全文
Prof. Dr. Barry M. Trost Dr. Dennis C. Koester Dr. Ehesan U. Sharif 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(8):2634-2638
The synthesis of densly functionized α‐silyl‐β‐hydroxyl vinylsilanes via ruthenium‐catalyzed multicomponent reaction (MCR) is reported herein. Exceptionally high regio‐ and diastereoselectivity was achieved by employing an unprecedented hydrosilylation of bifunctional silyl‐propargyl boronates. The simple protocol, mild reaction conditions, and unique tolerability of this method make it a valuable tool for the synthesis of highly elaborated building blocks. The one‐pot synthesis of stereodefined olefins, the generation of a valuable cyclohexene building block through a four‐component MCR, and further functionalization in an abundance of diastereoselective reactions is disclosed herein. 相似文献
18.
《Chemical record (New York, N.Y.)》2018,18(1):4-19
Tandem catalytic reaction is a promising strategy to improve the utilization efficiency of energy and resources. The conventional hybrid catalysts cannot readily realize the precisely controlled synthesis of target products due to the unrestricted, open reaction environment. Assembling the hybrid catalyst with multiple active sites into core‐shell structured capsule catalyst is one of the most effective ways to enhance the selectivity of desired products during a tandem catalysis process, because the core‐shell structure offers a space‐confined reaction field and synergistic effect. This review describes our recent progresses on the design and synthesis of core‐shell structured zeolite capsule catalysts developed for C1 chemistry and biomass conversion. The various synthesis methods for constructing the well‐defined zeolite capsule catalysts are described in detail. The applications of the capsule catalysts in catalysis, including the middle isoparaffins synthesis from syngas, one‐step synthesis of dimethyl ether, and liquid‐phase tandem reaction of glycerol conversion, are discussed, respectively. Our perspectives regarding the challenges and opportunities for future research in the field are also provided. 相似文献
19.
1,8‐Diazabicyclo[5.4.0]undec‐7‐ene immobilized on silica (SB‐DBU)Cl as a reusable and heterogeneous catalyst was applied for the one‐pot, three‐component synthesis of 2‐amino‐4,8‐dihydropyrano[3,2‐b]pyrane‐3‐carbonitriles and pyridopyrimidines, under solvent‐free conditions. The reaction was carried out at room temperature, and pure products were obtained in high yields and short reaction times (3–7 min). This work introduced an environmentally benign procedure for the synthesis of these classes of biological active compounds. 相似文献
20.
Palladium(0)‐Catalyzed Single and Double Isonitrile Insertion: A Facile Synthesis of Benzofurans,Indoles, and Isatins 下载免费PDF全文
Gopal Chandru Senadi Wan‐Ping Hu Siva Senthil Kumar Boominathan Prof. Dr. Jeh‐Jeng Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(3):998-1003
A palladium(0)‐catalyzed cascade process consisting of isonitrile insertion and α‐Csp3?H cross‐coupling can be achieved for the synthesis of benzofurans and indoles. The construction of isatins by a Pd‐catalyzed cascade reaction incorporating double isonitrile insertion, amination, and hydrolysis has also been achieved. The key features of this work include diverse heterocycle synthesis, phosphine‐ligand‐free reaction conditions, a one‐pot procedure, simple and commercially available starting materials, broad functional‐group compatibility, and moderate to good reaction yields. 相似文献