- Regio- and Stereoselective N-addition to an Open Bromo Vinyl Cation
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A protocol for the synthesis of thus far inaccessible bromo vinyl triflimides is presented. Our previously reported concept of assisted vinyl cation formation was engaged to achieve both a protonation of relatively electron poor bromo alkynes and a reaction with high regio- and stereoselectivity. To the best of our knowledge, this is the first stereoselective addition of an N-nucleophile to an open β-halovinyl cation.
- Chuchmareva, Marina,Collong, Arndt,Niggemann, Meike,Schr?der, Sebastian,Strauch, Christina
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supporting information
(2021/06/07)
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- Visible-Light-Promoted Formation of C—C and C—P Bonds Derived from Evolution of Bromoalkynes under Additive-Free Conditions: Synthesis of 1,1-Dibromo-1-en-3-ynes and Alkynylphosphine Oxides
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The controllable achievement of C—C and C—P bond formations is developed via visible-light-promoted bromoalkyne dimerization or its further transformation with secondary phosphine oxides. The 1,1-dibromo-1-en-3-ynes are formed when bromoalkyne is exposed to visible-light. While alkynylphosphine oxides are generated when bromoalkynes are mixed with secondary phosphine oxides.
- Xu, Hailong,Chen, Rui,Ruan, Hongjie,Ye, Ruyi,Meng, Ling-Guo
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supporting information
p. 873 - 878
(2021/03/04)
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- Copper-Catalyzed Perfluoroalkylation of Alkynyl Bromides and Terminal Alkynes
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A copper-catalyzed one-pot perfluoroalkylation of alkynyl bromides and terminal alkynes has been disclosed, and the corresponding perfluoroalkylated alkynes could be attained in good to excellent yields. The new straightforward transformation shows high efficiency (0.01-0.5 mol % catalyst loading), broad substrate scope, and remarkable functional group tolerance and provides a facile approach for useful application in life and material sciences.
- Fan, Shilu,Zheng, Chenggong,Zheng, Kaiting,Li, Junlan,Liu, Yaomei,Yan, Fangpei,Xiao, Hua,Feng, Yi-Si,Zhu, Yuan-Yuan
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supporting information
p. 3190 - 3194
(2021/05/05)
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- Fully Substituted Conjugate Benzofuran Core: Multiyne Cascade Coupling and Oxidation of Cyclopropenone
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An unprecedented C═C double bond cleavage of cyclopropenone and dioxygen activation by multiyne cascade coupling has been developed. This chemistry provides a novel, simple, and efficient approach to synthesize fully substituted conjugate benzofuran derivatives from simple substrates under mild conditions. The density functional theory (DFT) calculations reveal that the unique homolytic cleavages of cyclopropenone and molecular oxygen are crucial to the success of this reaction.
- Yao, Liangliang,Hu, Qiong,Bao, Li,Zhu, Wenjing,Hu, Yimin
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supporting information
p. 4971 - 4975
(2021/06/30)
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- Palladium-Catalyzed Carbonylation in the Synthesis of N-Ynonylsulfoximines
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Palladium-catalyzed carbonylation reactions with Cr(CO)6 as carbonyl source are key for the preparation of N-ynonylsulfoximines from NH-sulfoximines and bromoalkynes. The couplings proceed at room temperature with a wide range of substrate combinations affording the corresponding products in good yields. (Figure presented.).
- Ma, Ding,Wang, Chenyang,Kong, Deshen,Tu, Yongliang,Shi, Peng,Bolm, Carsten
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supporting information
p. 1330 - 1334
(2021/01/26)
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- A Unified Approach for Divergent Synthesis of Heterocycles via TMSOTf-Catalyzed Formal [3+2] Cycloaddition of Electron-Rich Alkynes
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We present a synthetic protocol for the construction of polysubstituted five-membered heterocycles via TMSOTf-catalyzed formal [3+2] cycloaddition of electron-rich alkynes, which features free from any metal, atom economy and water as the main by-product. Furthermore, alkenyl ether adduct has been verified as the key intermediate. Notably, by utilizing this approach, we can synthesize a broad range of polysubstituted furans, thiophenes and pyrroles, and extend this transformation to deliver fused-polyheterocycles. This reaction can be achieved on a gram scale and the corresponding products are intermediates for producing diverse potentially useful scaffolds. (Figure presented.).
- Chen, Ping,Cao, Wei,Li, Xiangqian,Shi, Dayong
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supporting information
p. 4789 - 4794
(2021/09/02)
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- Epoxyanthracene Derivatives and Dicarbonylation on Benzene Ring via Hexadehydro-Diels-Alder (HDDA) Derived Benzynes with Oxazoles
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A capture reaction of hexadehydro-Diels-Alder (HDDA) derived benzyne with various substituted oxazoles is reported. With methyl, hydrogen, or phenyl as the substituent at 2-position of oxazole, tetraynes afforded epoxyanthracene derivatives or underwent dicarbonylation on benzene ring. The reaction does not require any catalyst or additive. The mechanism behind the reaction was investigated. The obtained polycyclic product structure has potential application value in optoelectronic materials. The availability of dicarbonylated arene implies the uniqueness of HDDA benzyne reaction compared with traditional benzyne.
- Hu, Qiong,Hu, Yimin,Lei, Yu,Yang, Feihu,Zheng, Xiaojie,Zhu, Wenjing
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supporting information
(2021/11/22)
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- Direct oxidation ofN-ynylsulfonamides intoN-sulfonyloxoacetamides with DMSO as a nucleophilic oxidant
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N-Arylethynylsulfonamides are oxidized intoN-sulfonyl-2-aryloxoacetamides directly and efficiently with dimethyl sulfoxide (DMSO) as both an oxidant and solvent with microwave assistance. DFT calculations indicate that DMSO nucleophilically attacks the ethylic triple bond and transfers its oxygen atom to the triple bond to form zwitterionic anionicN-sulfonyliminiums to trigger the reaction. Then it nucleophilically attacks the generated iminium intermediates to accomplish the oxidationviathe second oxygen atom transfer. The current method provides a straightforward and efficient strategy to transform variousN-arylethynylsulfonamides intoN-sulfonyl-2-aryloxoacetamides, sulfonyl oxoacetimides, without any other electrophilic activators or oxidants.
- Dong, Jun,Fu, Duo,Sheng, Dongning,Wang, Jiayi,Xu, Jiaxi
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p. 40243 - 40252
(2021/12/31)
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- Access to Benzoxazepines and Fully Substituted Indoles via HDDA Coupling
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The HDDA-derived benzyne intermediate was captured by oxazolines based on the addition reaction of benzyne to the Ca?N double bond. Benzoxazepine derivatives, fused benzoxazepine derivatives, and fully substituted indoles are synthesized in one step. The reaction does not require any catalyst or additives. Possible reaction mechanisms are presented.
- Zheng, Xiaojie,Liu, Baohua,Yang, Feihu,Hu, Qiong,Yao, Liangliang,Hu, Yimin
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supporting information
p. 956 - 959
(2020/02/15)
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- Catalyst-Free [4+2] Cycloaddition of Ynamides with 2-Halomethyl Phenols to Construct 2-Amino-4 H-Chromenes and α-Halo Enamides Simultaneously
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We report the development of a facile protocol for the [4+2] cycloaddition of ynamides and 2-halomethyl phenols to afford the corresponding 2-amino-4H-chromenes and α-halo enamides under catalyst-free conditions. The reaction proceeds under mild condition
- Wen, Hao,Yan, Weibo,Chen, Ping,Li, Yu,Tang, Yu
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p. 12870 - 12881
(2020/11/02)
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- Phenanthrenes/dihydrophenanthrenes: The selectivity controlled by different benzynes and allenes
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A method for the intermolecular annulation of benzynes with allenes is disclosed. This protocol utilized allenes as an unconventional diene component for the selective synthesis of phenanthrenes and dihydrophenanthrenes under the control of different benzyne precursors, featuring high atom-economy and good functional group compatibility. Density functional theory (DFT) calculations reveal that different migratory routes of the aromatic C-H bond are crucial for the observed selectivity. This journal is
- Yao, Liangliang,Fang, Bo,Hu, Qiong,Lei, Yu,Bao, Li,Hu, Yimin
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supporting information
p. 15185 - 15188
(2020/12/21)
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- Monobrominated alkyne compound, preparation method and application thereof
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The invention belongs to the technical field of synthetic chemistry and discloses a monobrominated alkyne compound, a preparation method and an application thereof. The chemical structure formula of the monobrominated alkyne compound is as follows, wherei
- -
-
Paragraph 0038; 0039; 0040
(2019/02/04)
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- Gold-Catalyzed C(sp2)?C(sp) Coupling by Alkynylation through Oxidative Addition of Bromoalkynes
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A gold(I)-catalyzed cascade cyclization–alkynylation of allenoates using alkynyl bromide to generate β-alkynyl-γ-butenolides was investigated. Whereas alkynyl iodides afforded significant amounts of the homo-coupling of two lactone units, alkynyl bromides led to a selective reaction, and a broad functional group tolerance was observed. Under the optimized reaction conditions, it was possible to directly synthesize a large range of β-alkynyl-γ-butenolides in moderate to good yields without the need for any external oxidant.
- Yang, Yangyang,Schie?l, Jasmin,Zallouz, Sirine,G?ker, Verena,Gross, Jürgen,Rudolph, Matthias,Rominger, Frank,Hashmi, A. Stephen K.
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supporting information
p. 9624 - 9628
(2019/07/05)
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- Visible-Light-Promoted Oxo-Sulfonylation of Ynamides with Sulfonic Acids
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A visible-light-promoted oxo-sulfonylation of ynamides with sulfonic acids is reported, giving rise to a collection of functionalized α-sulfonylated amides in a straightforward manner. The reaction proceeds sequentially through a cascade of electrophilic addition and photoinduced sulfonyl radical-sustained skeleton rearrangement. The high atom economy, mild reaction conditions, and wide substrate scope comprised the merits of this synthetic transformation.
- Wang, Lu,Lu, Chengrong,Yue, Yanni,Feng, Chao
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supporting information
p. 3514 - 3517
(2019/05/16)
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- Gold Catalyzed Photoredox C1-Alkynylation of N-Alkyl-1,2,3,4- tetrahydroisoquinolines by 1-Bromoalkynes with UVA LED Light
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A synthetic method that combines [Au2(m-dppm)2]Cl2 (dppm=bis(diphenylphosphanyl)methane) and UVA LED (LED=light emitting diode) light (365 nm) to catalyze the regioselective C1-alkynylation of N-alkyl-1,2,3,4-tetrahydroisoquinolines (THIQs) with alkynyl bromides is described. The reaction mechanism was delineated to involve a reductive quench pathway to generate the two posited radical species of the nitrogen-containing heterocycle and organic halide. In contrast, radical formation via an oxidative quench pathway was suggested to be operative in analogous control experiments with a 1-iodoalkyne. The usefulness of this carbon-carbon bond forming strategy was also exemplified by its application to the formal synthesis of the opioid analgesic drug methopholine and synthesis of a protoberberine alkaloid derivative.
- Zhao, Yichao,Jin, Jianwen,Chan, Philip Wai Hong
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supporting information
p. 1313 - 1321
(2019/06/03)
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- Nickel-Catalyzed Reductive 1,2-Dialkynylation of Alkenes Bearing an 8-Aminoquinoline Directing Group
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An unprecedented nickel-catalyzed reductive 1,2-dialkynylation of alkenes bearing an 8-aminoquinoline directing group has been developed. This method proceeded through a migratory insertion/reductive-coupling process under mild conditions with a wide substrate scope and good functional group tolerance, providing direct access to the synthetically flexible 1,5-diynes. Moreover, the 1,2-dialkynylation products could be further converted to borate-ester- or azide-functionalized 1,5-dienes, ditriazole, β-diyne primary amide, and trisubstituted benzene.
- Pan, Rui,Shi, Cong,Zhang, Dongquan,Tian, Yang,Guo, Songjin,Yao, Hequan,Lin, Aijun
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supporting information
p. 8915 - 8920
(2019/11/14)
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- A Micellar Catalysis Strategy for Amidation of Alkynyl Bromides: Synthesis of Ynamides in Water
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Copper-catalyzed amidation of alkynyl bromides can be carried out in water for the first time, which is made possible by a micellar catalysis strategy using rosin-based surfactant APGS-550-M. The surfactant can be easily prepared from natural abundant biomass, resin acids. Studies as to substrate scope and reaction aqueous medium recycling showcase the ease and sustainability of this technology.
- Yang, Yunqin,Meng, Xiangtai,Zhu, Baolong,Jia, Ying,Cao, Xiaoji,Huang, Shenlin
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supporting information
p. 1166 - 1169
(2019/01/04)
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- Copper-catalyzed one-pot synthesis of alkynylphophonates
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Copper is found to be an effective catalyst for the preparation of alkynylphophonates. A novel copper-catalyzed one-pot synthesis of alkynylphophonates from terminal alkynes and dialkyl phosphites is developed which involves the haloalkynes intermediates. This method provides a unique and alternative approach to the well-documented oxidative coupling or arylpropiolic acid strategies.
- Song, Wang-Ze,Li, Jun-Hao,Li, Ming,He, Jun-Nan,Dong, Kun,Ullah, Karim,Zheng, Yu-Bin
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supporting information
p. 697 - 703
(2019/02/16)
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- Visible Light-Induced Difunctionalization of Alkynes: The Synthesis of Thiazoles and 1,1-Dibromo-1-en-3-ynes
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A visible light-induced cascade cyclization of thioamides with alkynes was developed to synthesize 1,3-thiozoles. The sulfur radical generated from thioamide via the single-electron transfer (SET) pathway was promoted by photocatalysis as a key intermediate in this reaction. When bromoalkynes were used as the substrate, the self-coupling products 1,1-dibromo-1-en-3-ynes were obtained in moderate yields, and an energy transfer pathway for this transformation promoted by visible-light photocatalysis was proposed.
- Huang, Xiaoying,Chen, Hui,Huang, Zhongzhi,Xu, Yanli,Li, Fangyao,Ma, Xianli,Chen, Yanyan
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p. 15283 - 15293
(2019/12/04)
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- Chloramine Salt Mediated Oxidative Halogenation of Terminal Alkynes with KI or NaBr: Practical Synthesis of 1-Bromoalkynes and 1-Iodoalkynes
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A direct oxidative halogenation of terminal alkynes has been realized using chloramine-B as the oxidant and KI or NaBr as the halogen source. This reaction enables a general and practical access to synthetically valuable 1-bromoalkynes and 1-iodoalkynes i
- Liu, Xiaozu,Chen, Guojun,Li, Chenglong,Liu, Peijun
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p. 2051 - 2055
(2018/09/18)
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- Copper-mediated synthesis of N-vinyl ynamides from N-vinyl carbamates
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Ynamides are versatile 3-atoms building blocks for organic synthesis as they participate in a variety of ionic, radical and pericyclic processes. Converting ynamides into 5-atom building blocks, such as the yet unreported N-vinyl ynamides, would open new avenues in this fascinating chemistry. We describe herein our efforts towards such goal and demonstrate that the cross-coupling between N-vinyl carbamates and bromo-alkynes using copper(I) thiophene carboxylate, 1,10-phenanthroline and tBuOK in DMSO is a reactive system with an improved profile compared to the classical ynamides syntheses. The advantages and limitations of this copper-mediated reaction are discussed.
- Le Fouler, Vincent,Duret, Guillaume,Bisseret, Philippe,Blanchard, Nicolas
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supporting information
p. 3349 - 3352
(2018/08/06)
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- Gold-Catalyzed Formal [4 + 2] Cycloaddition of 5-(Ethynylamino)pent-2-yn-1-yl Esters to 1,2,3,5-Tetrahydrobenzo [g] quinolines
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A synthetic method to prepare 1,2,3,5-tetrahydrobenzo[g]quinolines efficiently that relies on gold(I)-catalyzed cycloisomerization of 5-(ethynylamino)pent-2-yn-1-yl esters at room temperature under atmospheric conditions is described. The proposed reaction mechanism presents a unique instance of an in situ formed allenic ester and gold keteniminium species to undergo a formal [4 + 2] cycloaddition pathway.
- Chen, Xiaoyu,Merrett, James Theodore,Hong Chan, Philip Wai
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supporting information
p. 1542 - 1545
(2018/03/23)
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- A Highly Regio- and Stereoselective Syntheses of α-Halo Enamides, Vinyl Thioethers, and Vinyl Ethers with Aqueous Hydrogen Halide in Two-Phase Systems
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A metal-free regio- and stereoselective method is achieved for the preparation of (E)-configured α-halo enamides, vinyl thioethers, and vinyl ethers using aqueous HX (X = F, Cl, Br, I), which features high functional group compatibility and regio- and stereoselectivity, mild conditions, high efficiency, and rapid transformation. Additionally, the isomers could be yielded readily from the (E)-configured α-halo enamides via photocatalysis or under Sonogashira coupling conditions.
- Cao, Wei,Chen, Ping,Wang, Liang,Wen, Hao,Liu, Yu,Wang, Wanshu,Tang, Yu
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supporting information
p. 4507 - 4511
(2018/08/09)
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- Dual Gold-Catalyzed Formal Tetradehydro-Diels–Alder Reactions for the Synthesis of Carbazoles and Indolines
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This work reports a dual gold-catalyzed tetradehydro-Diels–Alder reaction for the synthesis of nitrogen-containing aromatic heterocycles. Under the catalytic system (IPrAuNTf2/DIPEA), indolines and carbazoles as well as other N-containing aromatic heterocycles were prepared in high yields with good functional group tolerance. Unlike the traditional thermal tetradehydro-Diels–Alder reactions, diluted reaction concentration and radical prohibitors are not required for this protocol. Experimental data support a mechanism involving gold vinylidene species, which undergoes a 6 π electrocyclization, followed with 1,2-hydrogen shift.
- Wang, Hong-Fa,Wang, Shi-Yue,Qin, Tian-Zhu,Zi, Weiwei
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supporting information
p. 17911 - 17914
(2018/11/23)
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- Synthesis of o-Allyloxy(ethynyl)benzene Derivatives by Cu-Catalyzed Suzuki–Miyaura-Type Reaction and Their Transformations into Heterocyclic Compounds
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We have found that Suzuki–Miyaura-type reactions of o-allyloxy(bromoethynyl)benzenes with arylboronic acids using a hydrazone/Cu catalyst system proceeded smoothly in iPrOH under mild conditions to afford the corresponding o-allyloxy(arylethynyl)benzene derivatives in good yields without decomposition of the allyloxy group. We have further demonstrated that annulation and enyne metathesis of the o-allyloxy(arylethynyl)benzene derivatives using transition-metal catalysts led to various heterocyclic compounds.
- Watanabe, Kohei,Mino, Takashi,Ishikawa, Eri,Okano, Miyu,Ikematsu, Tatsuya,Yoshida, Yasushi,Sakamoto, Masami,Sato, Kazuki,Yoshida, Kazuhiro
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supporting information
p. 2359 - 2368
(2017/05/01)
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- Controlled Reactivity of 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) in the Selective Synthesis of 1-(Bromoethynyl)arenes
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The nucleophilic reactivity of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) was completely controlled by the formation of monohydrate (DBU?H2O) in the synthesis of 1-(bromoethynyl)arenes from 1,1-dibromoalkenes. Differential reactivity of DBU in pr
- Krishna Moodapelly, Shiva,Sharma, Gangavaram V. M.,Ramana Doddi, Venkata
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supporting information
p. 1535 - 1540
(2017/05/05)
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- Highly efficient and recyclable catalyst for the direct chlorination, bromination and iodination of terminal alkynes
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Direct halogenation, including chlorination, bromination and iodination of terminal alkynes, are of great importance in organic synthesis. Here an efficient and recyclable nano-Ag/g-C3N4 catalyst system was developed and proved to be remarkably active with 39 examples varied from chlorination, bromination to iodination, of which 14 runs have yielded more than 95% of the product. Recycling of the catalyst was also achieved without obvious activity loss after several runs: 99% yield was observed even after 5 runs in the bromination of phenylacetylene. The catalysts system is of low cost and easy to be prepared, making this procedure versatile, convenient and economic.
- Shi, Wei,Guan, Zhipeng,Cai, Peng,Chen, Hao
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p. 199 - 204
(2017/08/10)
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- α-Imino Gold Carbenes from 1,2,4-Oxadiazoles: Atom-Economical Access to Fully Substituted 4-Aminoimidazoles
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A novel and atom-economical synthesis of fully substituted 4-aminoimidazoles via gold-catalyzed selective [3 + 2] annulation of 1,2,4-oxadiazoles with ynamides is reported. This protocol represents a new strategy to access α-imino gold carbenes, which corresponds to an unprecedented intermolecular transfer of N-acylimino nitrenes to ynamides. Moreover, the reaction proceeds with 100% atom economy, exhibits good functional group tolerance, and can be conducted in gram scale.
- Zeng, Zhongyi,Jin, Hongming,Xie, Jin,Tian, Bing,Rudolph, Matthias,Rominger, Frank,Hashmi, A. Stephen K.
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supporting information
p. 1020 - 1023
(2017/03/15)
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- Iridium-Catalyzed Highly Regioselective Azide-Ynamide Cycloaddition to Access 5-Amido Fully Substituted 1,2,3-Triazoles under Mild, Air, Aqueous, and Bioorthogonal Conditions
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A highly regioselective method to access 5-amido fully substituted 1,2,3-triazoles by iridium-catalyzed azide-ynamide cycloaddition under mild, air, aqueous, and bioorthogonal conditions is reported. The excellent regioselectivities may derive from the strong coordination between the carbonyl oxygen of ynamide and the -acidic iridium. Since the iridium ion is insensitive to oxygen/water and exhibits low cytotoxicity, it could catalyze this reaction in both organic and biological environments efficiently. Preparation in gram-scale and application in carbohydrates highlight this method.
- Song, Wangze,Zheng, Nan
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supporting information
p. 6200 - 6203
(2017/11/24)
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- Csp-Csp3 Bond Formation via Iron(III)-Promoted Hydroalkynylation of Unactivated Alkenes
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An iron(III)-promoted hydroalkynylation of unactivated alkenes toward Csp-Csp3 bond formation has been developed. Various alkenes, including mono-, di-, and trisubstituted alkenes, could all smoothly convert to structural diversified alkynes in this chemoselective protocol. Additionally, the scalability was unraveled and the further divergent transformations of products were conducted to demonstrate the synthetic utility.
- Shen, Yangyong,Huang, Bo,Zheng, Jing,Lin, Chen,Liu, Yu,Cui, Sunliang
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supporting information
p. 1744 - 1747
(2017/04/11)
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- Regioselective TfOH-mediated hydroamidation of ynamides with nitriles
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A new TfOH-mediated reaction of ynamides with nitriles as nucleophiles has been developed. The reaction works efficiently under mild reaction conditions to afford a new class of α-acylaminoenamides readily via the intermediacy of keteniminium ion. The reaction displays generality and a broad substrates scope. Additionally, the α-acylaminoenamides could be transformed to highly substituted pyridine, 4-aminopyrimidine or isoquinoline cores.
- Wang, Wan-Shu,Chen, Ping,Tang, Yu
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p. 2731 - 2739
(2017/04/14)
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- Gold-Catalyzed [4+2]- and [3+3]-Annulations of Ynamides with 1-Yn-3-ols to Access Six-Membered Carbocycles and Oxacycles via Three Distinct Cyclizations
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Three distinct strategies for catalytic annulations between ynamides and 1-yn-3-ols are described; the resulting carbo- and heterocycles were produced efficiently in one-pot operations using a gold catalyst. The chemoselectivities of these annulations are controlled by variations of the substituents of the ynamides and the 1-yn-3-ols. This reaction sequence involves initial alkoxylations of ynamides, followed by Claisen rearrangement of propargylic enol ethers, and ends with 6-endo-trig cyclizations of 1-allenyl-5-amide intermediates. Among these cascade annulations, the cyclizations of 5-allenyl-1-amides to yield 5,6-dihydro-2-pyranones and 6-alkylenecyclohex-2-ene-1-carboxamides are unprecedented in the literature. (Figure presented.).
- Giri, Sovan Sundar,Liu, Rai-Shung
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supporting information
p. 3311 - 3318
(2017/09/13)
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- Borane-catalyzed selective hydrosilylation of internal ynamides leading to β-silyl (Z)-enamides
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We have developed a borane-catalyzed regioand stereoselective hydrosilylation of internal ynamides for the first time. The scope of ynamide substrates and silane reactants was broad under mild reaction conditions, affording synthetically versatile β-silyl (Z)-enamide products. The observed stereoselectivity was reasoned to be due to the β-silicon effect on a postulated ketene iminium intermediate.
- Kim, Youngchan,Dateer, Ramesh B.,Chang, Sukbok
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supporting information
p. 190 - 193
(2017/11/27)
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- Regioselective fluorination of 1-(2,2-dibromovinyl)benzene derivatives with wet tetra-n-butylammonium fluoride: One-pot synthesis of (Z)-1-(2-bromo-1-fluorovinyl)benzenes
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A direct fluorination of 1-(2,2-dibromovinyl)benzene derivatives using wet tetra-n-butylammonium fluoride (TBAF·3H2O) as either a base or a fluorine source in toluene was accomplished, which provided (Z)-1-(2-bromo-1-fluorovinyl)benzene compoun
- Zhao, Mingzhu,Ming, Ling,Tang, Jialiang,Zhao, Xiaoming
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p. 416 - 419
(2016/02/19)
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- Gold-catalyzed [3+2]-annulations of α-aryl diazonitriles with ynamides and allenamides to yield 1-amino-1H-indenes
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Gold-catalyzed [3+2]-annulations of α-aryl diazonitriles with ynamides and allenamides yield 1-amino-1H-indenes in two distinct pathways; the success of these annulations relies on the high electrophilicity of α-cyano arylgold carbenes to activate an ionic pathway.
- Singh, Rahulkumar Rajmani,Pawar, Samir Kundlik,Huang, Min-Jie,Liu, Rai-Shung
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supporting information
p. 11434 - 11437
(2016/09/23)
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- Rapid access to unsymmetrical 1,3-diynes and 2,5-disubstituted thiophenes under ligand and Pd/Ni-free Cu-catalysis
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A Pd/Ni-free copper-catalysed tandem synthesis was realized for rapid access to unsymmetrical 1,3-diynes from 1,1-dibromoalkenes and terminal alkynes. This method was extended to the straightforward synthesis of unsymmetrical 2,5-disubstituted thiophenes
- Rao, Maddali L. N.,Islam, Sk Shamim,Dasgupta, Priyabrata
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p. 78090 - 78098
(2015/09/28)
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- Regioselective Synthesis of Polyheterohalogenated Naphthalenes via the Benzannulation of Haloalkynes
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Independent control of halide substitution at six of the seven naphthalene positions of 2-arylnaphthalenes is achieved through the regioselective benzannulation of chloro-, bromo-, and iodoalkynes. The modularity of this approach is demonstrated through the preparation of 44 polyheterohalogenated naphthalene products, most of which are difficult to access through known naphthalene syntheses. The outstanding regioselectivity of the reaction is both predictable and proven unambiguously by single-crystal X-ray diffraction for many examples. This synthetic method enables the rapid preparation of complex aromatic systems poised for further derivatization using established cross-coupling methods. The power and versatility of this approach makes substituted naphthalenes highly attractive building blocks for new organic materials and diversity-oriented synthesis.
- Lehnherr, Dan,Alzola, Joaquin M.,Lobkovsky, Emil B.,Dichtel, William R.
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supporting information
p. 18122 - 18127
(2015/12/24)
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- Cobalt(II)-catalyzed electrophilic alkynylation of 1,3-dicarbonyl compounds to form polysubstituted furans via π-π Activation
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Polysubstituted furans were obtained with excellent yields via the electrophilic alkynylation of 1,3-dicarbonyl compoundsws with phenyl- or ester-substituted brominated alkynes. The reaction is catalyzed by the inexpensive and readily available catalyst, cobalt(II) chloride, and has a wide substrate scope. The C(sp)-C(sp3) coupling occurs under mild conditions with short reaction times and does not require an inert atmosphere or ligands. It is proposed that the reaction proceeds through a chelation complex of cobalt(II) with the deprotonated 1,3-dicarbonyl compound.
- Roslan, Irwan Iskandar,Sun, Jiulong,Chuah, Gaik-Khuan,Jaenicke, Stephan
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supporting information
p. 719 - 726
(2015/03/18)
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- Gold-Catalyzed Intermolecular Nitrene Transfer from 2H-Azirines to Ynamides: A Direct Approach to Polysubstituted Pyrroles
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(Chemical Equation Presented). An effective gold-catalyzed intermolecular nitrene transfer by the reaction of 2H-azirines and ynamides is reported, which provides highly substituted pyrroles in a straightforward manner. This transformation proceeds under mild conditions and gives the polysubstituted pyrroles in good-to-excellent yields. Preliminary results indicate that a nongold carbenoid pathway is preferred for current pyrrole synthesis.
- Zhu, Lei,Yu, Yinghua,Mao, Zhifeng,Huang, Xueliang
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supporting information
p. 30 - 33
(2015/07/28)
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- Copper-catalyzed N-alkynylations of sulfoximines with bromoacetylenes
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N-Alkynylated sulfoximines have been obtained by copper-catalyzed cross-coupling reactions starting from NH-sulfoximines and bromoacetylenes in moderate to good yields. The reaction conditions are mild, and the substrate scope is wide.
- Chen, Xiao Yun,Wang, Long,Frings, Marcus,Bolm, Carsten
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supporting information
p. 3796 - 3799
(2014/08/05)
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- Facile and efficient synthesis of 1-haloalkynes via DBU-mediated reaction of terminal alkynes and N-haloimides under mild conditions
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Directly from terminal alkynes and with N-halosuccinimides (halo = Br and I) or N-cholorophthalimide as the halogen sources, DBU as the activator, 1-haloalkynes were prepared in good to excellent yields at room temperature. Bis(bromoalkyne) and bis(iodoal
- Li, Mengru,Li, Yueju,Zhao, Baozhong,Liang, Fushun,Jin, Long-Yi
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p. 30046 - 30049
(2014/08/05)
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- Alkyne aminohalogenation enabled by DBU-activated N-haloimides: Direct synthesis of halogenated enamines
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Activated by DBU, N-haloimides can be used as both halogen and nitrogen sources to achieve the difunctionalization of terminal alkynes, giving rise to useful halogenated enamines with high efficiency and high regio- and stereoselectivities. The cascade re
- Li, Mengru,Yuan, Haiyan,Zhao, Baozhong,Liang, Fushun,Zhang, Jingping
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supporting information
p. 2360 - 2363
(2014/03/21)
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- Copper catalyzed decarboxylative alkynylation of quaternary α-cyano acetate salts
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Cu-catalyzed decarboxylative alkynylation of quaternary α-cyano acetate salts with alkynyl bromides and alkynyl chlorides is described. This new reaction can be used for preparing functionalized butynenitrile derivatives.
- Feng, Yi-Si,Xu, Zhong-Qiu,Mao, Long,Zhang, Feng-Feng,Xu, Hua-Jian
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supporting information
p. 1472 - 1475
(2013/06/27)
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- Palladium-catalyzed alkynylative lactonization of unsaturated bicyclic carboxylic acids: Synthesis of fused polycyclic γ-lactone compounds
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Unsaturated bicyclic carboxylic acids undergo palladium-catalyzed coupling with bromoalkynes to produce γ-alkynyl lactones in moderate to good yields with excellent chemo- and regioselectivity. The reaction conditions were extremely mild, and functional groups such as methyl, methoxy, chloro, and bromo were tolerated under the optimized reaction conditions. Moreover, γ-chloroalkenyl lactones were facilely synthesized through chloropalladation/carboesterification of electron-deficient C≡C bonds by using molecular oxygen as the sole oxidant. Facile and tandem Pd-catalyzed synthesis of γ-alkynyl lactone and γ-chloroalkenyl lactone derivatives by using readily accessible bromoalkynes and unsaturated bicyclic carboxylic acids is reported. Two subsequent steps, namely, C(sp or sp 2)-C(sp3) bond formation and C-O bond formation, are catalyzed by a single Pd catalyst. The reactions proceed with good yields of the products. Copyright
- Sun, Ning,Li, Yibiao,Yin, Gengming,Jiang, Shaohua
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supporting information
p. 2541 - 2544
(2013/06/04)
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- Copper-catalyzed intermolecular oxidative cyclization of haloalkynes: Synthesis of 2-halo-substituted imidazo [1,2-α]pyridines, imidazo [1,2-α]pyrazines and imidazo [1,2-α]pyrimidines
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An efficient copper-catalyzed method for the synthesis of 2-haloimidazopyridines with aminopyridines and haloalkynes using molecular oxygen as oxidant in a one-pot manner has been developed. In this process, the reaction appears to be very general and suitable for the construction of a variety of 2-halo-substituted imidazopyridines, imidazopyrazines and imidazopyrimidines. The intermolecular oxidative diamination of haloalkynes was achieved for the first time. Importantly, the mild reaction conditions and the efficient conversion of the alkyl-substituted haloalkynes are great improvements over the existing methods. Moreover, the resultant 2-haloimidazo- [1,2-α]pyridines could be efficiently converted to other functionalized imidazopyridine products via substitution, coupling reactions and other transformations, which further indicates potential applications of this method in synthetic and pharmaceutical chemistry.
- Gao, Yang,Yin, Meizhou,Wu, Wanqing,Huang, Huawen,Jiang, Huanfeng
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supporting information
p. 2263 - 2273
(2013/10/01)
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- Synthesis of N-alkyl-substituted 4-quinolones via tandem alkenyl and aryl C-N bond formation
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N-Alkyl-substituted 4-quinolones are present as the key structural motif in many marketed drugs. An efficient one-step tandem amination approach was developed to afford N-alkyl-substituted 4-quinolones in high yields from easily accessible o-chloroaryl acetylenic ketones and functionalized alkyl amines. The approach complements and extends our previous work. Compared with other reported methods, the current method provides a very simple and convenient route. Georg Thieme Verlag Stuttgart · New York.
- Shao, Jun,Huang, Xiaomei,Hong, Xiaohu,Liu, Bingxin,Xu, Bin
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experimental part
p. 1798 - 1808
(2012/08/08)
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- Pd-catalyzed and CsF-promoted reaction of bromoalkynes with isocyanides: Regioselective synthesis of substituted 5-iminopyrrolones
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The palladium-catalyzed and CsF-promoted annulation reaction of bromoalkynes and isocyanides regioselectively affords a diverse set of 5-iminopyrrolone derivatives. This chemistry presumably proceeds through the bromoacrylamide intermediates, which can be readily prepared from the nucleophilic addition reaction of isocyanides to bromoalkynes in the presence of CsF.
- Li, Yibiao,Zhao, Jian,Chen, Huoji,Liu, Bifu,Jiang, Huanfeng
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supporting information; experimental part
p. 3545 - 3547
(2012/06/01)
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- Palladium-catalyzed bromoalkynylation of C-C double bonds: Ring-structure-dependent synthesis of 7-alkynyl norbornanes and cyclobutenyl halides
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Strain versus flexibility: The palladium-catalyzed reaction of haloalkynes with norbornene derivatives leads to 7-alkynyl norbornane products (see scheme). Key to the success of this reaction is the formation of a "bridging" palladium species, which can rearrange to result in a C-7 functionalization. The ring-structure-dependent [2+2] cycloaddition of haloalkynes with cyclooctene has been achieved in moderate to good yields under similar conditions. Copyright
- Li, Yibiao,Liu, Xiaohang,Jiang, Huanfeng,Liu, Bifu,Chen, Zhengwang,Zhou, Peng
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supporting information; experimental part
p. 6341 - 6345
(2011/09/13)
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- Palladium-catalyzed tandem amination reaction for the synthesis of 4-quinolones
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(Figure presented) An efficient palladium-catalyzed tandem amlnatlon approach was developed In one step to afford functlonallzed 4-qulnolones In good to excellent ylelds from easlly accessible o-haloaryl acetylenlc ketones and primary amines.
- Zhao, Tlankun,Xu, Bin
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supporting information; experimental part
p. 212 - 215
(2010/03/24)
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