- Electrochemical fluorosulfonylation of alkenes to access vicinal fluorinated sulfones derivatives
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Herein, we report a practical and efficient fluorosulfonylation of the various alkenes with sulfonyl radical sources (RSO2NHNH2) and Et3N·3HF as cost-effective fluorination reagents under mild conditions. Remarkably, this
- Zhao, Bin,Pan, Zichen,Zhu, Anqiao,Yue, Yanni,Ma, Mengtao,Xue, Fei
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supporting information
(2022/01/24)
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- Selective synthesis of iminodioxaspirononanes and diazaspirononanes using formic acid-activated Mn(III) oxidation of N1,N3-disubstitued malonamides with 1,1-diarylethenes
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The Mn(III)-based oxidation of N1,N3-disubstituted malonamides with alkenes by Kurosawa spirolactonization using malonic acid afforded iminodihydrofurans. A similar reaction with Mn(OAc)3, which was activated by HCO2
- El-Deeb, Ibrahim Yussif,Nakano, Y?ki,Nishino, Hiroshi,Shimoishi, Ryutaro,Wada, Ryosei
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- Intermolecular [4 + 2] process of N-acyliminium ions with simple olefins for construction of functional substituted-1,3-oxazinan-2-ones
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An efficient approach to functionalized 4,6-disubstituted-and 4,6,6-trisubstituted-1,3-oxazinan-2-ones skeleton has been developed through the reaction of semicyclic N,O-acetals 4a and 4b with 1,1-disubstituted ethylenes 5 or 8. As a result of such a [4 +
- Han, Xiaoli,Nie, Xiaodi,Feng, Yiman,Wei, Bangguo,Si, Changmei,Lin, Guoqiang
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supporting information
p. 3526 - 3530
(2021/06/12)
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- Photochemical Formal (4 + 2)-Cycloaddition of Imine-Substituted Bicyclo[1.1.1]pentanes and Alkenes
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Amines containing bridged bicyclic carbon skeletons are desirable building blocks for medicinal chemistry. Herein, we report the conversion of bicyclo[1.1.1]pentan-1-amines to a wide range of polysubstituted bicyclo[3.1.1]heptan-1-amines through a photochemical, formal (4 + 2)-cycloaddition of an intermediate imine diradical. To our knowledge, this is the first reported method to convert the bicyclo[1.1.1]pentane skeleton to the bicyclo[3.1.1]heptane skeleton. Hydrolysis of the imine products gives complex, sp3-rich primary amine building blocks.
- Harmata, Alexander S.,Sowden, Madison J.,Spiller, Taylor E.,Stephenson, Corey R. J.
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supporting information
p. 21223 - 21228
(2021/12/27)
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- Rhodium-Catalyzed meta-Selective C?H Carboxylation Reaction of 1,1-Diarylethylenes via Hydrorhodation-Rhodium Migration
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A meta-selective C?H carboxylation reaction of 1,1-diarylethylene derivatives with CO2 by using a rhodium catalyst with NaOiPr as a stoichiometric reductant has been achieved. Together with hydrogenation of the ethylene moiety, a carboxyl group was introduced to the meta-position of the aryl ring with high selectivity over the ortho-positions. Experimental and computational mechanistic studies indicate that this carboxylation reaction proceeds via hydrorhodation on the ethylene moiety, followed by 1,4-rhodium migration and successive 1,2-rhodium migration on the aryl ring. The use of a bulky phosphine ligand seems to be the key to this unusual aryl-to-aryl 1,2-rhodium shift.
- Caner, Joaquim,Iwasawa, Nobuharu,Saito, Takanobu,Toriumi, Naoyuki
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supporting information
p. 23349 - 23356
(2021/09/18)
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- Photoinduced Hydroarylation and Cyclization of Alkenes with Luminescent Platinum(II) Complexes
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Photoinduced hydroarylation of alkenes is an appealing synthetic strategy for arene functionalization. Herein, we demonstrated that aryl radicals generated from electron-deficient aryl chlorides/bromides could be trapped by an array of terminal/internal aryl alkenes in the presence of [Pt(O^N^C^N)] under visible-light (410 nm) irradiation, affording anti-Markovnikov hydroarylated compounds in up to 95 % yield. Besides, a protocol for [Pt(O^N^C^N)]-catalyzed intramolecular photocyclization of acrylanilides to give structurally diverse 3,4-dihydroquinolinones has been developed.
- Cheng, Hanchao,Lam, Tsz-Lung,Liu, Yungen,Tang, Zhou,Che, Chi-Ming
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supporting information
p. 1383 - 1389
(2020/11/30)
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- Direct Allylic C(sp3)?H and Vinylic C(sp2)?H Thiolation with Hydrogen Evolution by Quantum Dots and Visible Light
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Direct allylic C?H thiolation is straightforward for allylic C(sp3)?S bond formation. However, strong interactions between thiol and transition metal catalysts lead to deactivation of the catalytic cycle or oxidation of sulfur atom under oxidative condition. Thus, direct allylic C(sp3)?H thiolation has proved difficult. Represented herein is an exceptional for direct, efficient, atom- and step-economic thiolation of allylic C(sp3)?H and thiol S?H under visible light irradiation. Radical trapping experiments and electron paramagnetic resonance (EPR) spectroscopy identified the allylic radical and thiyl radical generated on the surface of photocatalyst quantum dots (QDs). The C?S bond formation does not require external oxidants and radical initiators, and hydrogen (H2) is produced as byproduct. When vinylic C(sp2)?H was used instead of allylic C(sp3)?H bond, the radical-radical cross-coupling of C(sp2)?H and S?H was achieved with liberation of H2. Such a unique transformation opens up a door toward direct C?H and S?H coupling for valuable organosulfur chemistry.
- Huang, Cheng,Ci, Rui-Nan,Qiao, Jia,Wang, Xu-Zhe,Feng, Ke,Chen, Bin,Tung, Chen-Ho,Wu, Li-Zhu
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supporting information
p. 11779 - 11783
(2021/04/21)
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- Visible-Light-Induced Meerwein Fluoroarylation of Styrenes
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An unprecedented approach for assembling a broad range of 1,2-diarylethane derivatives with fluorine-containing fully substituted carbon centers was developed. The protocol features straightforward operation, proceeds under metal-free condition, and accommodates a large variety of synthetically useful functionalities. The critical aspect to the success of this novel transformation lies in using aryldiazonium salts as both aryl radical progenitor and also as single electron acceptor which elegantly enables a radical-polar crossover manifold.
- Tang, Hai-Jun,Zhang, Bin,Xue, Fei,Feng, Chao
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supporting information
p. 4040 - 4044
(2021/05/26)
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- Electrochemistry enabled selective vicinal fluorosulfenylation and fluorosulfoxidation of alkenes
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Both sulfur and fluorine play important roles in organic synthesis, the life science, and materials science. The direct incorporation of these elements into organic scaffolds with precise control of the oxidation states of sulfur moieties is of great significance. Herein, we report the highly selective electrochemical vicinal fluorosulfenylation and fluorosulfoxidation reactions of alkenes, which were enabled by the unique ability of electrochemistry to dial in the potentials on demand. Preliminary mechanistic investigations revealed that the fluorosulfenylation reaction proceeded through a radical-polar crossover mechanism involving a key episulfonium ion intermediate. Subsequent electrochemical oxidation of fluorosulfides to fluorosulfoxides were readily achieved under a higher applied potential with the adventitious H2O in the reaction mixture.
- Jiang, Yimin,Shi, Zhaojiang,Wu, Jinnan,Wu, Shaofen,Ye, Keyin,Yu, Yi,Yuan, Yaofeng
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supporting information
(2021/11/17)
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- Direct 1,2-Dicarbonylation of Alkenes towards 1,4-Diketones via Photocatalysis
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1,4-Dicarbonyl compounds are intriguing motifs and versatile precursors in numerous pharmaceutical molecules and bioactive natural compounds. Direct incorporation of two carbonyl groups into a double bond at both ends is straightforward, but also challenging. Represented herein is the first example of 1,2-dicarbonylation of alkenes by photocatalysis. Key to success is that N(n-Bu)4+ not only associates with the alkyl anion to avoid protonation, but also activates the α-keto acid to undergo electrophilic addition. The α-keto acid is employed both for acyl generation and electrophilic addition. By tuning the reductive and electrophilic ability of the acyl precursor, unsymmetric 1,4-dicarbonylation is achieved for the first time. This metal-free, redox-neutral and regioselective 1,2-dicarbonylation of alkenes is executed by a photocatalyst for versatile substrates under extremely mild conditions and shows great potential in biomolecular and drug molecular derivatization.
- Chen, Bin,Cheng, Yuan-Yuan,Hou, Hong-Yu,Lei, Tao,Tung, Chen-Ho,Wu, Li-Zhu,Yu, Ji-Xin
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supporting information
p. 26822 - 26828
(2021/11/17)
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- Base-promoted addition of DMA with 1,1-diarylethylenes: Application to a total synthesis of (-)-sacidumlignan B
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A base-promoted addition of DMA (N,N-dimethylacetamide) to 1,1-diarylethylenes has been developed, and it provides a new strategy for the synthesis of N,N-dimethyl-4,4-diarylbutanamides from 1,1-diarylethylenes at room temperature. This method allows us to achieve the goal of synthesizing (-)-sacidumlignan B, and provides simple operation and broad substrate scope by avoiding the use of transition metal catalysts.
- Luo, Zhen-Biao,Peng, Yu,Wang, Ya-Wen
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p. 2054 - 2057
(2020/03/27)
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- Cu/Ni-Catalyzed Cyanomethylation of Alkenes with Acetonitrile for the Synthesis of β,γ-Unsaturated Nitriles
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We have developed a protocol for the Cu/Ni-catalyzed cyanomethylation of alkenes with acetonitrile for the synthesis of β,γ-unsaturated nitriles. This is the first example of a direct coupling of the alkene sp2 C - H bond and the acetonitrile sp3 C - H bond for the preparation of β,γ-unsaturated nitriles. Acetonitrile, an inexpensive and stable solvent, is demonstrated to be a useful cyanomethyl source. The combination of copper and nickel catalysts resulted in a high reaction efficiency.
- Jian, Hong,Shen, Zengming,Zhang, Saisai
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p. 6143 - 6150
(2020/05/22)
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- Synthesis of N-Heterocycles by Reductive Cyclization of Nitroalkenes Using Molybdenum Hexacarbonyl as Carbon Monoxide Surrogate
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The development of a method that uses molybdenum hexacarbonyl [Mo(CO)6] as carbon monoxide (CO) surrogate for the palladium-catalyzed reductive cyclization of nitroalkenes into indoles or thienopyrroles is reported. Several types of nitroalkenes could be transformed into the desired products in excellent yields and in most cases with complete regioselectivities and higher yields than those previously reported with palladium/CO system.
- Su, Zhiyou,Liu, Bo,Liao, Hongze,Lin, Hou-Wen
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supporting information
p. 4059 - 4066
(2020/06/21)
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- Halogenation of 1,1-diarylethylenes by N-halosuccinimides
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An efficient method for the preparation of 2,2-diarylvinyl halides from the corresponding 1,1-diarylethylenes has been developed. N-Halosuccinimides (N-bromosuccinimide or N-chlorosuccinimide) were used as the halogenation reagents. The practicability of this method is highlighted by its simple operation, broad substrate scope and capability for large-scale reaction.
- Zhang, Ge,Bai, Rui-Xue,Li, Chu-Han,Feng, Chen-Guo,Lin, Guo-Qiang
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supporting information
p. 1658 - 1662
(2018/12/11)
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- Copper-Catalyzed 1,2-Methoxy Methoxycarbonylation of Alkenes with Methyl Formate
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Reported here is a copper-catalyzed 1,2-methoxy methoxycarbonylation of alkenes by an unprecedented use of methyl formate as a source of both the methoxy and the methoxycarbonyl groups. This reaction transforms styrene and its derivatives into value-added β-methoxy alkanoates and cinnamates, as well as medicinally important five-membered heterocycles, such as functionalized tetrahydrofurans, γ-lactones, and pyrrolidines. A ternary β-diketiminato-CuI-styrene complex, fully characterized by NMR spectroscopy and X-ray crystallographic analysis, is capable of catalyzing the same transformation. These findings suggest that pre-coordination of electron-rich alkenes to copper might play an important role in accelerating the addition of nucleophilic radicals to electron-rich alkenes, and could have general implications in the design of novel radical-based transformations.
- Budai, Balázs,Leclair, Alexandre,Wang, Qian,Zhu, Jieping
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supporting information
p. 10305 - 10309
(2019/06/27)
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- Radical C?H Bond Trifluoromethylation of Alkenes by High-Valent Copper(III) Trifluoromethyl Compounds
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A general and selective method is developed that allows direct vinylic C?H bond trifluoromethylation of 1,1-diarylalkenes by a high-valent copper(III) trifluoromethyl complex, producing biologically active trifluoromethylated alkenes (as well as trifluoro
- Zhang, Hao-Ran,Xiao, Chang,Zhang, Song-Lin,Zhang, Xiaoming
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supporting information
p. 5305 - 5310
(2019/11/22)
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- Cobaloxime Catalysis: selective synthesis of alkenylphosphine oxides under visible light
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Direct activation of H-phosphine oxide to react with an unsaturated carbon-carbon bond is a straightforward approach for accessing alkenylphosphine oxides, which shows significant applications in both synthetic and material fields. However, expensive metals and strong oxidants are typically required to realize the transformation. Here, we demonstrate the utility of earth-abundant cobaloxime to convert H-phosphine oxide into its reactive radical species under visible light irradiation. The radical species thus generated can be utilized to functionalize alkenes and alkynes without any external photosensitizer and oxidant. The coupling with terminal alkene generates E-alkenylphosphine oxide with excellent chemo- A nd stereoselectivity. The reaction with terminal alkyne yields linear E-alkenylphosphine oxide via neutral radical addition, while addition with internal ones generates cyclic benzophosphine oxides and hydrogen. Mechanistic studies on radical trapping experiments, electron spin resonance studies, and spectroscopic measurements confirm the formation of phosphinoyl radical and cobalt intermediates that are from capturing the electron and proton eliminated from H-phosphine oxide. The highlight of our mechanistic investigation is the dual role played by cobaloxime, viz., both as the visible light absorber to activate the P(O)-H bond as well as a hydrogen transfer agent to influence the reaction pathway. This synergetic feature of the cobaloxime catalyst preforming multiple functions under ambient condition provides a convergent synthetic approach to vinylphosphine oxides directly from H-phosphine oxides and alkenes (or alkynes).
- Liu, Wen-Qiang,Lei, Tao,Zhou, Shuai,Yang, Xiu-Long,Li, Jian,Chen, Bin,Sivaguru, Jayaraman,Tung, Chen-Ho,Wu, Li-Zhu
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supporting information
p. 13941 - 13947
(2019/09/30)
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- Cobaloxime Catalysis: Selective Synthesis of Alkenylphosphine Oxides under Visible Light
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Direct activation of H-phosphine oxide to react with an unsaturated carbon-carbon bond is a straightforward approach for accessing alkenylphosphine oxides, which shows significant applications in both synthetic and material fields. However, expensive metals and strong oxidants are typically required to realize the transformation. Here, we demonstrate the utility of earth-abundant cobaloxime to convert H-phosphine oxide into its reactive radical species under visible light irradiation. The radical species thus generated can be utilized to functionalize alkenes and alkynes without any external photosensitizer and oxidant. The coupling with terminal alkene generates E-alkenylphosphine oxide with excellent chemo- and stereoselectivity. The reaction with terminal alkyne yields linear E-alkenylphosphine oxide via neutral radical addition, while addition with internal ones generates cyclic benzophosphine oxides and hydrogen. Mechanistic studies on radical trapping experiments, electron spin resonance studies, and spectroscopic measurements confirm the formation of phosphinoyl radical and cobalt intermediates that are from capturing the electron and proton eliminated from H-phosphine oxide. The highlight of our mechanistic investigation is the dual role played by cobaloxime, viz., both as the visible light absorber to activate the P(O)-H bond as well as a hydrogen transfer agent to influence the reaction pathway. This synergetic feature of the cobaloxime catalyst preforming multiple functions under ambient condition provides a convergent synthetic approach to vinylphosphine oxides directly from H-phosphine oxides and alkenes (or alkynes).
- Liu, Wen-Qiang,Lei, Tao,Zhou, Shuai,Yang, Xiu-Long,Li, Jian,Chen, Bin,Sivaguru, Jayaraman,Tung, Chen-Ho,Wu, Li-Zhu
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supporting information
p. 13941 - 13947
(2019/09/30)
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- Regioselective Diboron-Mediated Semireduction of Terminal Allenes
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A method for the regioselective reduction of the terminal double bond of 1,1-disubstituted allenes has been developed. In the presence of a palladium catalyst, tetrahydroxydiboron and stoichiometric water, allene semireduction proceeds in high yield to afford Z-alkenes selectively.
- Gates, Ashley M.,Santos, Webster L.
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supporting information
p. 4619 - 4624
(2019/12/11)
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- Synergistic combination of visible-light photo-catalytic electron and energy transfer facilitating multicomponent synthesis of β-functionalized α,α-diarylethylamines
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A synthetic strategy with the visible-light photo-catalytic synergistic combination of electron and energy transfer processes has been developed. The mild reaction conditions allow the radical-radical cross-coupling phenomenon for the multicomponent synthesis of β-arylsulfonyl(diarylphosphinoyl)-α,α-diarylethyl-amines from readily available arylsulfinic acids (diarylphosphine oxides), 1,1-diarylethylenes and arylazides.
- Wu, Yanan,Zhang, Yipin,Jiang, Mingjie,Dong, Xunqing,Jalani, Hitesh B.,Li, Guigen,Lu, Hongjian
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supporting information
p. 6405 - 6408
(2019/06/07)
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- Synthesis of 2,2-diarylvinyl phenyl selenides by dehydration of 2-hydroxyalkyl phenyl selenides
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A novel route to 2,2-diarylvinyl phenyl selenides is reported by dehydration of the corresponding 2,2-diaryl-2-hydroxyethyl phenyl selenides, prepared by oxyphenylselenenylations of the corresponding 1,1-diarylethylenes, upon treatment with p-toluenesulfonic acid.
- Stuhr-Hansen, Nicolai
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- Regioselective Transfer Hydrodeuteration of Alkenes with a Hydrogen Deuteride Surrogate Using B(C6F5)3 Catalysis
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A regioselective hydrodeuteration of alkenes using monodeuterated cyclohexa-1,4-dienes as surrogates for hydrogen deuteride (HD) gas is reported. The metal-free process proceeds under B(C6F5)3 catalysis presumably by deuteride abstraction to form borodeuteride [DB(C6F5)3]a and highly Br?nsted-acidic Wheland intermediates. Low catalyst loadings (2.5 mol %) are used, and the reaction proceeds at room temperature.
- Walker, Johannes C. L.,Oestreich, Martin
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supporting information
p. 6411 - 6414
(2018/10/20)
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- Facile synthesis of indolelactones using Mn(III)-based oxidative substitution-cyclization reaction
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Based on the oxidation of indole with Mn(OAc)3 in the presence of 1,1-diarylethenes affording 3-vinyl-substituted indoles, a similar oxidation using indole-2-carboxylic acids was evaluated in order to effectively introduce the substituent group to the C-3 position of the indolecarboxylic acids. The coupling reaction followed by oxidative cyclization smoothly proceeded at room temperature in an AcOH-HCO2H mixed solvent to give the desired indolelactones in high yields. The reaction details, the structure determination of the products and a brief reaction mechanism are described.
- Inoue, Takeshi,Nishino, Hiroshi
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p. 431 - 450
(2019/07/31)
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- Advanced Synthesis of Dihydrofurans: Effect of Formic Acid on the Mn(III)-Based Oxidation
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The Mn(III)-based oxidation of a tertiary alkylamine, such as nitrilotris(ethane-2,1-diyl) tris(3-oxobutanoate) (1) with 1,1-diphenylethene (2a), effectively proceeded in an acetic acid-formic acid mixed solvent to give nitrilotris(ethane-2,1-diyl) tris(2-methyl-5,5-diphenyl-4,5-dihydrofuran-3-carboxylate) (3). Other typical Mn(III)-based reactions of various β-diketo esters 4a-e, 2,4-pentanedione (6a), malonic acid (6b), and diethyl malonate (6c) with 1,1-diarylthenes 2a-d were also investigated in a similar acetic acid-formic acid mixed solvent and the reaction rate was accelerated and the product yield increased.
- Matsumoto, Risa,Nishino, Hiroshi
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supporting information
p. 1807 - 1816
(2015/08/06)
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- Copper-catalyzed oxidative amination and allylic amination of alkenes
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Enamines and enamides are useful synthetic intermediates and common components of bioactive compounds. A new protocol for their direct synthesis by a net alkene C-H amination and allylic amination by using catalytic Cu II in the presence of MnO2 is reported. Reactions between N-aryl sulfonamides and vinyl arenes furnish enamides, allylic amines, indoles, benzothiazine dioxides, and dibenzazepines directly and efficiently. Control experiments further showed that MnO2 alone can promote the reaction in the absence of a copper salt, albeit with lower efficiency. Mechanistic probes support the involvement of nitrogen-radical intermediates. This method is ideal for the synthesis of enamides from 1,1-disubstituted vinyl arenes, which are uncommon substrates in existing oxidative amination protocols. A new protocol for the direct synthesis of enamides and allylic amines by oxidative N-H/C-H coupling of N-sulfonylanilines with vinylarenes is presented. The reaction works in both inter- and intramolecular modes and is catalyzed by copper salts by using MnO2 as the stoichiometric oxidant (see scheme). Nitrogen heterocycles including indoles, benzothiazine dioxides, and dibenzazepines can be formed. Copyright
- Liwosz, Timothy W.,Chemler, Sherry R.
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supporting information
p. 12771 - 12777
(2013/10/01)
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- Ruthenium(IV)-catalyzed markovnikov addition of carboxylic acids to terminal alkynes in aqueous medium
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The dimeric bis(allyl)ruthenium(IV) complex [{RuCl(μ-Cl)( η3:η3-C10H16)}2] (C10H16 = 2,7-dimethylocta-2,6-diene-1,8-diyl) (5) and several mononuclear species trans-[RuCl2(η3: η3-C10H16)(L)] (L = two-electron-donor ligand) (6) derived from 5 have been checked as catalysts for the addition of carboxylic acids onto terminal alkynes using water as a green reaction medium. The best results in terms of activity and regioselectivity were obtained with the mononuclear derivative trans-[RuCl2(η3: η3-C10H16)(PPh3)] (6a), which was able to promote the selective Markovnikov addition of both aromatic and aliphatic carboxylic acids to a large variety of terminal alkynes, enynes, and diynes as well as propargylic alcohols. In this way, a wide number of enol esters and β-oxo esters could be synthesized in moderate to good yields under mild conditions (60 °C) in an aqueous medium.
- Cadierno, Victorio,Francos, Javier,Gimeno, Jose
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experimental part
p. 852 - 862
(2011/04/15)
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- Aluminum (III) chloride - Catalyzed reaction of 1,1,1-trichloroethane with aromatic compounds: A facile synthesis of symmetrical 1,1-diphenylethylenes
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1,1,1-Trichloroethane, under Friedel - Crafts reaction conditions, reacts efficiently with variety of aromatic substrates 1 to afford symmetrical 1,1-diarylethylenes 2 in excellent yields.
- Jayachandran,Phukan,Nikalje,Daniel,Sudalai
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p. 954 - 957
(2007/10/03)
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- Activation conditions play a key role in the activity of zeolite CaY: NMR and product studies of Bronsted acidity
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CaY, activated under different conditions, was characterized with 1H, 31P, and 1H/27A] double resonance MAS NMR. The 1H MAS NMR spectra of CaY, calcined in an oven at 500 °C, shows resonances from H2O (bound to Ca2+ and the zeolite framework), CaOH+, aluminum hydroxides, silanols, and Bronsted acid sites. No evidence for Lewis acidity is observed on adsorption of trimethylphosphine, and an estimate of ≈16 Bronsted acid sites per unit cell is obtained for this sample. CaY activated in an oven at higher temperatures contains less water, but all the other species are still present. In contrast, CaY activated by slow ramping of the temperature under vacuum to 500 or 600 °C shows a much lower concentration of Bronsted acid sites (1/unit cell). Again, no evidence for Lewis acidity was observed. These NMR results have been utilized to understand the very different product distributions that are observed for reactions of 1,1- and 1,2-diarylethylenes in zeolite CaY activated in an oven (in air) and under vacuum. Samples with high concentrations of Bronsted acid sites react stoichiometrically with these sites, yielding diarylalkanes. At low concentrations, the Bronsted acid sites can act catalytically resulting in isomerization reactions.
- Kao, Hsien-Ming,Grey, Clare P.,Pitchumani, Kasi,Lakshminarasimhan,Ramamurthy
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p. 5627 - 5638
(2007/10/03)
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- Synthesis and double olefin extrusion of 2,2,6,6-tetraaryl-1,5-dioxa-4λ5-phosphaspiro[3.3]heptanes
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The title compounds were synthesized by cyclization and dehydration of the corresponding bis(β-hydroxyalkyl)phosphine oxides with Appel's reagent. Since these compounds were very moisture sensitive to hydrolyze to the starting bis(β-hydroxyalkyl)phosphine oxides except for tetrakis(4-nitrophenyl) derivative, their in-situ generation and thermolysis were carried out to give two molar equivalents of the corresponding olefins in good yield in sharp contrast to tetrakis(trifluoromethyl) derivative.
- Kawashima, Takayuki,Okazaki, Rei,Okazaki, Renji
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p. 379 - 386
(2007/10/03)
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- Substituted 6,11-ethano-6,11-dihydrobenzo[b] quinolizinium salts and compositions and methods of use thereof
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Substituted 6,11-ethano-6,11-dihydrobenzo[b]quinolizinium salts, pharmaceutical compositions containing them, and methods for the treatment of neurodegenerative disorders or neurotoxic injuries utilizing them, wherein the substituted 6,11-ethano-6,11-dihydrobenzo[b]quinolizinium salts have the formula: STR1 wherein: R1, R2, R3, R4, R5, R6, R7, X and p are as defined in the specification.
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- Substituted heterocyclylisoquinolinium salts and compositions and method of use thereof
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Substitutued heterocyclylisoquinolinium salts, pharmaceutical compositions containing them and methods for the treatment or prevention of neurodegenerative disorders or neurotoxic injuries utilizing them.
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- Discovery of 6,11-ethano-12,12-diaryl-6,11-dihydrobenzo[b]quinolizinium cations, a novel class of N-methyl-D-aspartate antagonists
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6,11-Ethano-12,12-diaryl-6,11-dihydrobenzo[b]quinolizinium cations 8, a novel class of N-methyl-D-aspartate (NMDA) antagonists acting at the phencyclidine site, have been identified. Structure-activity relationship studies around the lead compound 8a led
- Subramanyam,Mallamo,Dority Jr.,Earley,Kumar,Aimone,Ault,Miller,Luttinger,DeHaven-Hudkins
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- Substituent Effect Studies of Aryl-Assisted Solvolyses. I. The Acetolysis of 2,2-Bis(substituted phenyl)ethyl p-Toluenesulfonates
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The substituent effect on the acetolysis of 2,2-bis(substituted phenyl)ethyl p-toluenesulfonates at 90.10 deg C can be described accurately in terms of the Yukawa-Tsuno (LArSR) relationship, giving a ρ value of -4.44 and an r value of 0.53. The substituent effect correlation of this system carrying two aryls is quite comparable to that of the 2-methyl-2-phenylpropyl system carrying a single aryl group, suggesting the close similarity in the structure of the transition states between the systems. The results can be reasonably accounted for on the basis of the accepted mechanism of this reaction, involving a rate-determining aryl-assisted transition state where only one aryl group of the two β-aryl groups participates.
- Fujio, Mizue,Maeda, Yasuyuki,Goto, Mutsuo,Saeki, Yoshihiro,Mishima, Masaaki,Tsuno, Yuho
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p. 3015 - 3020
(2007/10/02)
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