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1.
Organocatalyzed Cascade Aza‐Michael/Michael Addition for the Asymmetric Construction of Highly Functionalized Spiropyrazolone Tetrahydroquinolines
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An organocatalyzed diastereo‐ and enantioselective cascade aza‐Michael/Michael addition of 2‐tosylaminoenones to unsaturated pyrazolones has been developed to afford novel chiral spiropyrazolone tetrahydroquinolines containing three contiguous stereocenters. This cascade reaction proceeded well with 2 mol % chiral bifunctional tertiary amine squaramide catalyst to give the desired products in excellent yields (up to 99 %) with excellent diastereoselectivity (up to >25:1 diastereomeric ratio) and high enantioselectivity (up to 91 % enantiomeric excess). 相似文献
2.
《中国化学》2018,36(1):20-24
A highly regio‐, diastereo‐ and enantioselective addition of 2‐acyl imidazoles or 2‐acyl pyridines with allenes promoted by Rh/Lewis acid synergistically catalytic system is described. This atom economic approach leads to the formation of the branched allylic alkylated products including acyclic quaternary all‐carbon stereogenic centres in good yields with good to excellent diastereo‐ and enantioselectivities. Kinetic studies reveal that the rate‐determining step in this process is the oxidative addition of Rh(I) with C—H bond. 相似文献
3.
Combining Organocatalysis and Lanthanide Catalysis: A Sequential One‐Pot Quadruple Reaction Sequence/Hetero‐Diels–Alder Asymmetric Synthesis of Functionalized Tricycles
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Dr. Simon Dochain M. Sc. Fabrizio Vetica Dr. Rakesh Puttreddy Prof. Dr. Kari Rissanen Prof. Dr. Dieter Enders 《Angewandte Chemie (International ed. in English)》2016,55(52):16153-16155
A stereoselective one‐pot synthesis of functionalized complex tricyclic polyethers has been achieved using the combination of secondary amine and lanthanide catalysis. This one‐pot quadruple reaction/Hetero‐Diels–Alder sequence gave good yields (per step) as well as excellent diastereo‐ and enantioselectivities. Furthermore, the particular combination of lanthanide complexes with organocatalysis is one of the first examples described for sequential catalysis. 相似文献
4.
Asymmetric Dearomatization of Indoles through a Michael/Friedel–Crafts‐Type Cascade To Construct Polycyclic Spiroindolines
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Xiaohu Zhao Prof. Xiaohua Liu Hongjiang Mei Jing Guo Dr. Lili Lin Prof. Xiaoming Feng 《Angewandte Chemie (International ed. in English)》2015,54(13):4032-4035
A highly efficient asymmetric dearomatization of indoles was realized through a cascade reaction between 2‐isocyanoethylindole and alkylidene malonates catalyzed by a chiral N,N′‐dioxide/MgII catalyst. Fused polycyclic indolines containing three stereocenters were afforded in good yields with excellent diastereo‐ and enantioselectivities through a Michael/Friedel–Crafts/Mannich cascade. When 2‐substituted 2‐isocyanoethylindoles were used, spiroindoline derivatives were obtained through a Michael/Friedel–Crafts reaction. 相似文献
5.
Enantioselective Synthesis of Pyrrole‐Based Spiro‐ and Polycyclic Derivatives by Iridium‐Catalyzed Asymmetric Allylic Dearomatization and Controllable Migration Reactions
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Dr. Chun‐Xiang Zhuo Qiang Cheng Dr. Wen‐Bo Liu Qiang Zhao Prof. Dr. Shu‐Li You 《Angewandte Chemie (International ed. in English)》2015,54(29):8475-8479
The first highly diastereo‐ and enantioselective synthesis of five‐membered spiro‐2H‐pyrroles was achieved using an Ir‐catalyzed asymmetric allylic dearomatization reaction. The spiro‐2H‐pyrrole derivatives readily undergo a controllable and stereospecific allylic migration under acid catalysis, providing polycyclic pyrrole derivatives in excellent yields and ee values. Additionally, the novel Ir‐complex K1 , derived from [Ir(cod)Cl]2 (cod=1,5‐cyclooctadiene) and N‐benzhydryl‐N‐phenyldinaphthophosphoramidite (BHPphos), showed excellent control of both diastereo‐ and enantioselectivities. 相似文献
6.
Ruthenium(II)/Chiral Brønsted Acid Co‐Catalyzed Enantioselective Four‐Component Reaction/Cascade Aza‐Michael Addition for Efficient Construction of 1,3,4‐Tetrasubstituted Tetrahydroisoquinolines
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Dr. Jun Jiang Xiaochu Ma Dr. Changge Ji Dr. Zhenqiu Guo Taoda Shi Dr. Shunying Liu Prof. Wenhao Hu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(6):1505-1509
An elegant synergistic catalytic system comprising a ruthenium complex with a chiral Brønsted acid was developed for a four‐component Mannich/cascade aza‐Michael reaction. The ruthenium‐associated ammonium ylides successfully trapped with in situ generated imines indicates a stepwise process of proton transfer in the ruthenium‐catalyzed carbenoid N?H insertion reaction. The different decomposition abilities of various ruthenium complexes towards diazo compounds were well explained by the calculated thermodynamic data. The transformation features a mild, rapid, and efficient method for the synthesis of enantiomerically pure 1,3,4‐tetrasubstituted tetrahydroquinolines bearing a quaternary stereogenic carbon center from simple starting precursors in moderate yields with high diastereo‐ and enantioselectivity. 相似文献
7.
Brønsted Acid Catalyzed [3+2]‐Cycloaddition of 2‐Vinylindoles with In Situ Generated 2‐Methide‐2H‐indoles: Highly Enantioselective Synthesis of Pyrrolo[1,2‐a]indoles
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Dr. Kalisankar Bera Prof. Dr. Christoph Schneider 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(21):7074-7078
Pyrrolo[1,2‐a]indoles are privileged structural elements of many natural products and pharmaceuticals. An efficient one‐step process for their highly diastereo‐ and enantioselective synthesis, comprising a direct [3+2]‐cycloaddition, has been developed. A chiral BINOL‐derived phosphoric acid catalyzes the reaction of in situ‐generated 2‐methide‐2H‐indoles with 2‐vinylindoles, furnishing the target products incorporating three contiguous stereogenic centers as single diastereoisomers and with excellent yields and enantioselectivities. 相似文献
8.
A Synthetic Route to Chiral Dihydrobenzothiazines through Ring Opening of Activated Aziridines with 2‐Halothiophenols/Copper‐Powder‐Mediated C−N Cyclization
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Prof. Dr. Manas K. Ghorai Masthanvali Sayyad Yerramsetti Nanaji Sourita Jana 《化学:亚洲杂志》2015,10(7):1480-1489
A simple protocol for the synthesis of dihydrobenzothiazines through regio‐ and stereoselective SN2‐type ring opening of N‐tosylaziridines with sulfur nucleophiles followed by copper‐powder‐mediated intramolecular C?N cyclization in excellent yields (up to 95 %) with high diastereo‐ and enantioselectivity (up to >99 %) is reported. 相似文献
9.
Arun Suneja Henning Jakob Loui Christoph Schneider 《Angewandte Chemie (International ed. in English)》2020,59(14):5536-5540
We describe herein a highly diastereo‐ and enantioselective [4+3]‐cycloannulation of ortho‐quinone methides and carbonyl ylides to furnish functionalized oxa‐bridged dibenzooxacines with excellent yields and stereoselectivity in a single synthetic step. The combination of rhodium and chiral phosphoric acid catalysis working in concert to generate both transient intermediates in situ provides direct access to complex bicyclic products with two quaternary and one tertiary stereogenic centers. The products may be further functionalized into valuable and enantiomerically highly enriched building blocks. 相似文献
10.
Diastereo‐ and Enantioselective Palladium‐Catalyzed Dearomative [3+2] Cycloaddition of 3‐Nitroindoles
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Diastereo‐ and enantioselective cycloaddition of 3‐nitroindoles with vinyl aziridine was realized under Pd‐catalysis using commercially available Walphos as the ligand, affording pyrroloindolines in high yields with high diastereo‐ and enantioselectivities. The reaction can be scaled up to a gram scale and the reaction products are easily converted to amino pyrroloindoline and other pyrroloindoline derivatives. 相似文献
11.
Enantioselective Construction of Spiroindolines with Three Contiguous Stereogenic Centers and Chiral Tryptamine Derivatives via Reactive Spiroindolenine Intermediates
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Dr. Chun‐Xiang Zhuo Yong Zhou Qiang Cheng Lin Huang Prof. Dr. Shu‐Li You 《Angewandte Chemie (International ed. in English)》2015,54(47):14146-14149
The highly efficient synthesis of the enantioenriched spiroindolines by iridium‐catalyzed asymmetric allylic dearomatization and reduction is presented. Spiroindolines containing three contiguous stereogenic centers were obtained with excellent diastereo‐ and enantioselectivity. In addition, a chiral tryptamine derivative could be easily accessed in good yield with excellent ee value through an unprecedented dearomatization/retro‐Mannich/hydrolysis cascade reaction of an indole derivative. 相似文献
12.
Construction of Spirocyclic Oxindoles through Regio‐ and Stereoselective [3+2] or [3+2]/[4+2] Cascade Reaction of α,β‐Unsaturated Imines with 3‐Isothiocyanato Oxindole
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Dan Du Dr. Qin Xu Xiao‐Ge Li Prof. Dr. Min Shi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(14):4733-4737
On the basis of asymmetric regioselective [3+2] or [3+2]/[4+2] cascade reaction of 3‐isothiocyanato oxindoles with C=C and C=N bonds of α,β‐unsaturated methanesulfonamides, diversified S‐containing heterocyclic spirooxindole derivatives could be obtained in high yields along with good to excellent diastereo‐ and enantioselectivities under mild conditions in the presence of cinchona alkaloid‐derived organocatalysts. 相似文献
13.
Anastassia Matviitsuk Scott E. Denmark 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(36):12616-12620
A catalytic, enantio‐, and diastereoselective formation of sulfenyl acetals bearing multiple stereogenic centers is reported. Alkenyl aldehydes undergo a chiral thiiranium ion initiated cascade starting with intramolecular capture by a formyl group and termination by capture with HFIP solvent. This method provides a one‐pot synthesis of dihydropyran and 1,3‐disubstituted isochroman acetals in good to excellent yield and with high levels of diastereo‐ (up to >99:1 dr) and enantiocontrol (up to 99:1 er). 相似文献
14.
Anastassia Matviitsuk Scott E. Denmark 《Angewandte Chemie (International ed. in English)》2019,58(36):12486-12490
A catalytic, enantio‐, and diastereoselective formation of sulfenyl acetals bearing multiple stereogenic centers is reported. Alkenyl aldehydes undergo a chiral thiiranium ion initiated cascade starting with intramolecular capture by a formyl group and termination by capture with HFIP solvent. This method provides a one‐pot synthesis of dihydropyran and 1,3‐disubstituted isochroman acetals in good to excellent yield and with high levels of diastereo‐ (up to >99:1 dr) and enantiocontrol (up to 99:1 er). 相似文献
15.
Catalytic Asymmetric Reactions of 4‐Substituted Indoles with Nitroethene: A Direct Entry to Ergot Alkaloid Structures
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Simone Romanini Emilio Galletti Dr. Lorenzo Caruana Prof. Andrea Mazzanti Prof. Fahmi Himo Dr. Stefano Santoro Prof. Mariafrancesca Fochi Prof. Luca Bernardi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(49):17578-17582
A domino Friedel–Crafts/nitro‐Michael reaction between 4‐substituted indoles and nitroethene is presented. The reaction is catalyzed by BINOL‐derived phosphoric acid catalysts, and delivers the corresponding 3,4‐ring‐fused indoles with very good results in terms of yields and diastereo‐ and enantioselectivities. The tricyclic benzo[cd]indole products bear a nitro group at the right position to serve as precursors of ergot alkaloids, as demonstrated by the formal synthesis of 6,7‐secoagroclavine from one of the adducts. DFT calculations suggest that the outcome of the reaction stems from the preferential evolution of a key nitronic acid intermediate through a nucleophilic addition pathway, rather than to the expected “quenching” through protonation. 相似文献
16.
Intramolecular Aza‐Diels–Alder Reactions of ortho‐Quinone Methide Imines: Rapid,Catalytic, and Enantioselective Assembly of Benzannulated Quinolizidines
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M. Sc. Martin Kretzschmar M. Sc. Fabian Hofmann M. Sc. Daniel Moock Prof. Dr. Christoph Schneider 《Angewandte Chemie (International ed. in English)》2018,57(17):4774-4778
Aza‐Diels–Alder reactions (ADARs) are powerful processes that furnish N‐heterocycles in a straightforward fashion. Intramolecular variants offer the additional possibility of generating bi‐ and polycyclic systems with high stereoselectivity. We report herein a novel Brønsted acid catalyzed process in which ortho‐quinone methide imines tethered to the dienophile via the N substituent react in an intramolecular ADAR to form complex quinolizidines and oxazinoquinolines in a one‐step process. The reactions proceed under very mild conditions, with very good yields and good to very good diastereo‐ and enantioselectivities. Furthermore, the process was extended to a domino reaction that efficiently combines substrate synthesis, ortho‐quinone methide imine formation, and ADAR. 相似文献
17.
Asymmetric Synthesis of Tetrahydroindolizines by Bimetallic Relay Catalyzed Cycloaddition of Pyridinium Ylides
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Dong Zhang Prof. Dr. Lili Lin Jian Yang Prof. Dr. Xiaohua Liu Prof. Dr. Xiaoming Feng 《Angewandte Chemie (International ed. in English)》2018,57(38):12323-12327
A highly enantioselective synthesis of tetrahydroindolizines by catalytic multicomponent cycloaddition reactions of diazoacetate, pyridine, and alkenyloxindole was developed. Under the relay catalysis, involving an achiral iron(III) catalyst and chiral N,N′‐dioxide‐scandium(III) complex, a series of tetrahydroindolizines bearing different substituents were obtained in moderate to high yields (up to 99 %) with excellent diastereo‐ and enantioselectivities (up to >19:1 d.r., 99 % ee). 相似文献
18.
Jianke Pan Jia‐Hong Wu Hongkui Zhang Xiaoyu Ren Jian‐Ping Tan Lixiang Zhu Hong‐Su Zhang Chunhui Jiang Tianli Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(22):7503-7508
The first enantioselective aza‐Darzens reaction of cyclic imines with α‐halogenated ketones was realized under mild reaction conditions by using amino‐acid‐derived bifunctional phosphonium salts as phase‐transfer promoters. A variety of structurally dense tri‐ and tetrasubstituted aziridine derivatives, containing benzofused heterocycles as well as spiro‐structures, were readily synthesized in high yields with excellent diastereo‐ and enantioselectivities (up to >20:1 d.r. and >99.9 % ee). The highly functionalized aziridine products could be easily transformed into different classes of biologically active compounds. 相似文献
19.
Enantioselective Synthesis of Cyclobutylboronates via a Copper‐Catalyzed Desymmetrization Approach
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Dr. Manuel Guisán‐Ceinos Dr. Alejandro Parra Víctor Martín‐Heras Dr. Mariola Tortosa 《Angewandte Chemie (International ed. in English)》2016,55(24):6969-6972
The first catalytic enantioselective synthesis of cyclobutylboronates, by using a chiral copper(I) complex, is reported. A broad variety of cyclobutanes have been prepared with consistently high levels of diastereo‐ and enantiocontrol. Moreover, this method constitutes the first report of an enantioselective desymmetrization of meso‐cyclobutenes to prepare chiral cyclobutanes. 相似文献
20.
Assembly of Fluorinated Quaternary Stereogenic Centers through Catalytic Enantioselective Detrifluoroacetylative Aldol Reactions
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Chen Xie Lingmin Wu Dr. Jianlin Han Prof. Dr. Vadim A. Soloshonok Dr. Yi Pan 《Angewandte Chemie (International ed. in English)》2015,54(20):6019-6023
A Cu‐catalyzed asymmetric detrifluoroacetylative aldol addition reaction of 2‐fluoro‐1,3‐diketones/hydrates to aldehydes in the presence of base and chiral bidentate ligand was developed. The reaction was carried out under convenient conditions and tolerated a wide range of substrates, resulting in fluorinated quaternary stereogenic α‐fluoro‐β‐hydroxy ketone products with good chemical yields, diastereo‐ and enantioselectivities. This catalytic asymmetric detrifluoroacetylative aldol addition reaction provides a new approach for the preparation of biologically relevant products containing C? F quaternary stereogenic centers. 相似文献