- 1,1′-(Ethenylidene)bis(4-chlorobenzene)
-
The title compound, C14H10Cl2, crystallizes as colourless prisms with two symmetry-independent molecules in the unit cell. Numerous intermolecular C-H...π interactions dominate in the crystal structure, where C-H...Cl and long Cl...Cl contacts are also observed.
- Jabbar, Md. Abdul,Aritome, Isao,Shimakoshi, Hisashi,Hisaeda, Yoshio
-
-
Read Online
- Electrochemical fluorosulfonylation of alkenes to access vicinal fluorinated sulfones derivatives
-
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
-
supporting information
(2022/01/24)
-
- Selective synthesis of iminodioxaspirononanes and diazaspirononanes using formic acid-activated Mn(III) oxidation of N1,N3-disubstitued malonamides with 1,1-diarylethenes
-
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
-
-
- Intermolecular [4 + 2] process of N-acyliminium ions with simple olefins for construction of functional substituted-1,3-oxazinan-2-ones
-
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
-
supporting information
p. 3526 - 3530
(2021/06/12)
-
- Direct Allylic C(sp3)?H and Vinylic C(sp2)?H Thiolation with Hydrogen Evolution by Quantum Dots and Visible Light
-
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
-
supporting information
p. 11779 - 11783
(2021/04/21)
-
- Visible-Light-Induced Meerwein Fluoroarylation of Styrenes
-
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
-
supporting information
p. 4040 - 4044
(2021/05/26)
-
- Electrochemistry enabled selective vicinal fluorosulfenylation and fluorosulfoxidation of alkenes
-
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
-
supporting information
(2021/11/17)
-
- Direct 1,2-Dicarbonylation of Alkenes towards 1,4-Diketones via Photocatalysis
-
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
-
supporting information
p. 26822 - 26828
(2021/11/17)
-
- Synthesis of Quinolines via the Metal-free Visible-Light-Mediated Radical Azidation of Cyclopropenes
-
We report the synthesis of quinolines using cyclopropenes and an azidobenziodazolone (ABZ) hypervalent iodine reagent as an azide radical source under visible-light irradiation. Multisubstituted quinoline products were obtained in 34-81% yield. The reaction was most efficient for 3-trifluoromethylcyclopropenes, affording valuable 4-trifluoromethylquinolines. The transformation probably proceeds through the cyclization of an iminyl radical formed by the addition of the azide radical on the cyclopropene double bond, followed by ring-opening and fragmentation.
- Smyrnov, Vladyslav,Muriel, Bastian,Waser, Jerome
-
supporting information
p. 5435 - 5439
(2021/07/21)
-
- Visible-Light Photoredox-Catalyzed Dicarbofunctionalization of Styrenes with Oxime Esters and CO2: Multicomponent Reactions toward Cyanocarboxylic Acids and γ-Keto Acids
-
A photoredox-catalyzed dicarbofunctionalization of styrenes with oxime esters and CO2 has been achieved. Notably, a series of four-, five-, or six-membered cyclic ketone oximes worked well to furnish a wide range of ε-, ζ-, and η-cyanocarboxylic acids in good yields. Furthermore, a series of γ-keto acids also could be obtained by employing acyclic ketone oxime esters as the carbonyl radical precursor. It provides convergent access to diverse biologically important cyanocarboxylic and γ-keto acids.
- Bai, Junxue,Li, Miao,Zhou, Cong,Sha, Yu,Cheng, Jiang,Sun, Jianwei,Sun, Song
-
supporting information
p. 9654 - 9658
(2021/12/14)
-
- Cu/Ni-Catalyzed Cyanomethylation of Alkenes with Acetonitrile for the Synthesis of β,γ-Unsaturated Nitriles
-
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
-
p. 6143 - 6150
(2020/05/22)
-
- DI-, TRI- AND TETRAPHENYLINDANE DERIVATIVES AND THEIR USE IN ORGANIC ELECTRONICS
-
The present invention relates to indane derivatives of the formula (I) and mixtures thereof, wherein X is selected from groups of the formulae -A-NH2 or -A-(NAr2), wherein A is a chemical bond or phenylene which is unsubstituted or substituted
- -
-
Page/Page column 85
(2020/06/01)
-
- Enantioselective Radical-Polar Crossover Reactions of Indanonecarboxamides with Alkenes
-
Highly efficient asymmetric intermolecular radical-polar crossover reactions were realized by combining a chiral N,N′-dioxide/NiII complex catalyst with Ag2O under mild reaction conditions. Various terminal alkenes and indanonecarboxamides/esters underwent radical addition/cyclization reactions to afford spiro-iminolactones and spirolactones with good to excellent yields (up to 99 %) and enantioselectivities (up to 97 % ee). Furthermore, a range of different radical-mediated oxidation/elimination or epoxide ring-opening products were obtained under mild reaction conditions. The Lewis acid catalysts exhibited excellent performance and precluded the strong background reaction.
- Cao, Weidi,Feng, Xiaoming,Liu, Xiaohua,Wu, Wangbin,Xu, Xi,Yu, Han,Zhang, Xiying
-
supporting information
p. 4846 - 4850
(2020/02/11)
-
- Bromomethyl Silicate: A Robust Methylene Transfer Reagent for Radical-Polar Crossover Cyclopropanation of Alkenes
-
A general protocol for visible-light-induced cyclopropanation of alkenes was developed with bromomethyl silicate as a methylene transfer reagent, offering a robust tool for accessing highly valuable cyclopropanes. In addition to α-aryl or methyl-substituted Michael acceptors and styrene derivatives, the unactivated 1,1-dialkyl ethylenes were also shown to be viable substrates. Apart from realizing the cyclopropanation of terminal alkenes, the methyl transfer reaction has been further demonstrated to be amenable to the internal olefins. The photocatalytic cyclopropanation of 1,3-bis(1-arylethenyl)benzenes was also achieved, giving polycyclopropane derivatives in excellent yields. With late-stage cyclopropanation as the key strategy, the synthetic utility of this transformation was also demonstrated by the total synthesis of LG100268.
- Luo, Wenping,Fang, Yewen,Zhang, Li,Xu, Tianhang,Liu, Yongjun,Li, Yan,Jin, Xiaoping,Bao, Jiakan,Wu, Xiaodong,Zhang, Zongyong
-
p. 1778 - 1781
(2020/03/11)
-
- Base-promoted addition of DMA with 1,1-diarylethylenes: Application to a total synthesis of (-)-sacidumlignan B
-
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
-
supporting information
p. 2054 - 2057
(2020/03/27)
-
- Iodobenzene-catalyzed oxidative cleavage of olefins to carbonyl compounds
-
A metal-free approach for the oxidative cleavage of carbon–carbon double bonds of olefins to carbonyl compounds was established by using oxidant m-CPBA and non-metallic organocatalyst PhI in toluene/H2O. A broad scope of aromatic olefins was used. All the reactions proceeded smoothly at 35 °C in short reaction time to furnish the respective mono- and double carbonyl compounds selectively in moderate to good yields.
- Du, Lele,Wang, Zechao,Wu, Junliang
-
-
- Method for synthesizing alpha,beta-unsaturated selenium compound
-
The invention belongs to the field of organic selenium chemistry, and particularly relates to a method for synthesizing an alpha,beta-unsaturated selenium compound. The compound is synthesized by using an aryl boronic acid compound, elemental selenium and a diarylethene compound as reaction substrates. The method avoids toxic selenium-mercury reagents and toxic selenide reagents, conforms to the modern green development concept, and provides a green and economical method for synthesizing unsaturated selenium compounds in the future.
- -
-
Paragraph 0062-0065
(2019/11/28)
-
- Halogenation of 1,1-diarylethylenes by N-halosuccinimides
-
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
-
supporting information
p. 1658 - 1662
(2018/12/11)
-
- Photocatalytic, Phosphoranyl Radical-Mediated N-O Cleavage of Strained Cycloketone Oximes
-
A photoinduced, phosphoranyl radical-mediated protocol for the direct N-O cleavage of strained cycloketone oximes via a polar/SET crossover process was developed for the first time. This visible-light-driven direct N-O activation mode for oxime offers beneficial features such as streamlined synthetic process and versatile photochemical reactivities. Consequently, the alkenes and α-trifluoromethyl alkenes with varied electronic and structural features acted as competent radical receptors in this protocol, enabling facile accesses to a range of elongated cyano and/or gem-difluoroalkene-bearing compounds.
- Xia, Peng-Ju,Ye, Zhi-Peng,Hu, Yuan-Zhuo,Song, Dan,Xiang, Hao-Yue,Chen, Xiao-Qing,Yang, Hua
-
supporting information
p. 2658 - 2662
(2019/04/25)
-
- Copper-Catalyzed 1,2-Methoxy Methoxycarbonylation of Alkenes with Methyl Formate
-
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
-
supporting information
p. 10305 - 10309
(2019/06/27)
-
- Oxidative [4+2] Cycloaddition of α-(N-Arylamino) Carbonyls with Aryl Alkenes by Multiple C-H Functionalizations and [1,2]-Aryl Shifts
-
A new, general copper-catalyzed oxidative tandem [4+2] cycloaddition of α-(N-arylamino) carbonyl compounds with aryl alkenes to produce highly substituted quinolines has been developed, which allows the formation of three new C-C bonds through a sequence of multiple C-H functionalizations, annulation, and [1,2]-aryl shifts.
- Wei, Wen-Ting,Teng, Fan,Li, Yang,Song, Ren-Jie,Li, Jin-Heng
-
supporting information
p. 6285 - 6288
(2019/09/06)
-
- Radical C?H Bond Trifluoromethylation of Alkenes by High-Valent Copper(III) Trifluoromethyl Compounds
-
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
-
supporting information
p. 5305 - 5310
(2019/11/22)
-
- Cobaloxime Catalysis: selective synthesis of alkenylphosphine oxides under visible light
-
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
-
supporting information
p. 13941 - 13947
(2019/09/30)
-
- Cobaloxime Catalysis: Selective Synthesis of Alkenylphosphine Oxides under Visible Light
-
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
-
supporting information
p. 13941 - 13947
(2019/09/30)
-
- Regioselective Diboron-Mediated Semireduction of Terminal Allenes
-
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.
-
supporting information
p. 4619 - 4624
(2019/12/11)
-
- Synergistic combination of visible-light photo-catalytic electron and energy transfer facilitating multicomponent synthesis of β-functionalized α,α-diarylethylamines
-
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
-
supporting information
p. 6405 - 6408
(2019/06/07)
-
- Temperature-controlled divergent synthesis of 4-alkoxy- or 4-alkenyl-chromanes via inverse electron-demand cycloaddition with in situ generated ortho-quinone methides
-
The temperature-controlled divergent synthesis of 4-alkoxy- or 4-alkenyl-chromanes via inverse electron-demand cycloaddition with in situ generated ortho-quinone methides under identical reaction conditions except for thermal condition has been developed. At room temperature, the reaction generated 4-methoxychromanes, whereas the reaction performed at room temperature to 100 °C gave 4-alkenylchromanes. Trifluoromethanesulfonic acid was efficiently suitable in the reaction to give the 4-substituted chromanes. This divergent synthetic strategy exhibits a new method giving carbon–carbon or carbon–oxygen bond by controlling the reaction temperature.
- Tanaka, Kenta,Kishimoto, Mami,Hoshino, Yujiro,Honda, Kiyoshi
-
supporting information
p. 1841 - 1845
(2018/04/11)
-
- Sunlight-Driven Synthesis of Triarylethylenes (TAEs) via Metal-Free Mizoroki–Heck-Type Coupling
-
A protocol for the preparation of substituted triarylethylenes (TAEs) was developed by using arylazo sulfones as substrates in the presence of 1,1-diarylethylenes. The process took place efficiently in the absence of any (photo)catalyst upon exposure of the reaction mixture to (simulated) sunlight.
- Onuigbo, Louis,Raviola, Carlotta,Di Fonzo, Andrea,Protti, Stefano,Fagnoni, Maurizio
-
supporting information
p. 5297 - 5303
(2018/09/14)
-
- Electrophilic borylation of terminal alkenes with BBr3/2,6-disubstituted pyridines
-
A variety of terminal alkenes, as well as heteroaromatic compounds, are borylated by the combined use of BBr3/2,6-dichloropyridine (B3) or BBr3/2,6-lutidine (B5). α,α-Diarylalkenes prefer the former reagent combination, while other alkenes prefer the latter. Mechanistic considerations strongly suggest that the former and latter reactions proceed through electrophilic substitution reactions with BBr3 and [BBr2·B5]+BBr4-, respectively.
- Tanaka, Shinya,Saito, Yuki,Yamamoto, Takaya,Hattori, Tetsutaro
-
supporting information
p. 1828 - 1831
(2018/04/14)
-
- Facile synthesis of indolelactones using Mn(III)-based oxidative substitution-cyclization reaction
-
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
-
p. 431 - 450
(2019/07/31)
-
- Advanced Synthesis of Dihydrofurans: Effect of Formic Acid on the Mn(III)-Based Oxidation
-
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
-
supporting information
p. 1807 - 1816
(2015/08/06)
-
- Electrochemical dechlorination of 4,4′-(2,2,2-trichloroethane-1,1-diyl)bis(chlorobenzene) (DDT) at silver cathodes
-
Cyclic voltammetry and controlled-potential (bulk) electrolysis have been employed to investigate the reduction of 4,4′-(2,2,2-trichloroethane-1,1-diyl)bis(chlorobenzene) (DDT) at silver cathodes in dimethylformamide (DMF) containing 0.050 M tetramethylammonium tetrafluoroborate (TMABF4). In addition, this work has been extended to the individual reductions of two degradation products, namely 4,4′-(2,2-dichloroethane-1,1-diyl)bis(chlorobenzene) (DDD) and 4,4′-(ethene-1,1-diyl)bis(chlorobenzene) (DDNU). At a scan rate of 100 mV s-1, cyclic voltammograms for irreversible reduction of DDT at a silver electrode exhibit four prominent cathodic peaks in DMF and CH3CN, and three prominent cathodic peaks in DMSO. On the other hand, reduction of DDD and DDNU at silver in DMF-0.050 M TMABF4displays four and two irreversible peaks, respectively. Carbon-chlorine bonds of the -CCl3moiety of DDT and of the -CHCl2moiety of DDD are reduced more easily at silver than at glassy carbon. Bulk electrolyses of DDT at a silver gauze cathode in DMF-0.050 M TMABF4afford a potential-dependent mixture of products that includes DDD, DDNU, 4,4′-(2,2-dichloroethene-1,1-diyl)bis(chlorobenzene) (DDE), 4,4′-(2-chloroethene-1,1-diyl)bis(chlorobenzene) (DDMU), 4,4′-(2-chloroethane-1,1-diyl)bis(chlorobenzene) (DDMS), 1-chloro-4-(1-phenylvinyl)benzene (PVB), 1,1′-diphenylethylene (DPE), and 1,1′-ethylidenebisbenzene (EBB). However, at more negative potentials, the principal products are completely dechlorinated DPE and EBB. Dechlorination of DDT at silver appears to proceed via a series of steps involving carbanion intermediates arising from direct reduction of alkyl and aryl carbon-chlorine bonds along with hydroxide-promoted E2 elimination of chloride. When DMF-d7was used as solvent, no evidence for deuterium atom incorporation into any product was seen, which indicates that radical intermediates do not play a significant role in the reduction of DDT.
- McGuire, Caitlyn M.,Peters, Dennis G.
-
p. 423 - 430
(2014/12/10)
-
- Direct C-H trifluoromethylation of di- and trisubstituted alkenes by photoredox catalysis
-
Background: Trifluoromethylated alkene scaffolds are known as useful structural motifs in pharmaceuticals and agrochemicals as well as functional organic materials. But reported synthetic methods usually require multiple synthetic steps and/or exhibit lim
- Tomita, Ren,Yasu, Yusuke,Koike, Takashi,Akita, Munetaka
-
supporting information
p. 1099 - 1106
(2014/06/09)
-
- Ruthenium(IV)-catalyzed markovnikov addition of carboxylic acids to terminal alkynes in aqueous medium
-
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
-
experimental part
p. 852 - 862
(2011/04/15)
-
- Ruthenium-catalyzed synthesis of β-oxo esters in aqueous medium: Scope and limitations
-
The ability of the hydrosoluble ruthenium(ii) complexes [RuCl 2(η6-arene)(PTA)] 3a-d, [RuCl2(η 6-arene)(PTA-Bn)] 4a-d, [RuCl2(η6-arene) (DAPTA)] 5a-d, [RuCl2(η6-arene)(TPPMS)] 6a-d (arene = C6H6, p-cymene, 1,3,5-C6H3Me 3, C6Me6) to promote the atom-economic formation of β-oxo esters, by addition of carboxylic acids to terminal propargylic alcohols in water has been explored. Scope, limitations and catalyst recycling have been evaluated using the most active catalyst [RuCl 2(η6-C6H6)(TPPMS)], 6a.
- Cadierno, Victorio,Francos, Javier,Gimeno, Jose
-
experimental part
p. 135 - 143
(2010/05/18)
-
- Enhanced reactivity of hydrophobic vitamin B12 towards the dechlorination of DDT in ionic liquid
-
The electrolytic reductive dechlorination of 1,1-bis(p-chlorophenyl)-2,2,2- trichloroethane (DDT) in the ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]) in the presence of a cobalamin derivative afforded 1,1′-(ethylidene)bis(4-chlorobenzene) (DDO) and 1,1′-(ethenylidene)bis(4-chlorobenzene) (DDNU) with 1,1′-(2- chloroethylidene)bis(4-chlorobenzene) (DDMS); the enhanced reactivity, as well as the recyclability of the cobalamin derivative catalyst in IL, makes the present system more efficient for the development of "green" technologies. The Royal Society of Chemistry.
- Jabbar, Md. Abdul,Shimakoshi, Hisashi,Hisaeda, Yoshio
-
p. 1653 - 1655
(2008/02/07)
-
- Palladated Kaiser oxime resin as precatalyst for the Heck reaction in organic and aqueous media
-
A particular Kaiser oxime resin derived palladacycle is an efficient precatalyst for the Heck reaction with aryl iodides and bromides in DMF and in aqueous solvents under relatively moderate temperatures (110 °C and 120 °C) and high TON up to 105. Poisoning studies indicate that this polymer acts as a precatalyst. The polymer has been reused after recycling with low to moderate leaching of Pd(0). Georg Thieme Verlag Stuttgart.
- Alacid, Emilio,Nájera, Carmen
-
p. 2959 - 2964
(2008/03/11)
-
- 3,5-Bis(trifluoromethyl)phenyl sulfones in the direct Julia-Kocienski olefination
-
3,5-Bis(trifluoromethyl)phenyl (BTFP) sulfones 7 have been employed in the Julia-Kocienski olefination reaction with carbonyl compounds. Sulfones 7 are readily prepared in high yields (64-97%) from commercially available 3,5-bis(trifluoromethyl)thiophenol through an alkylation/oxidation two-step sequence. The stability of metalated BTFP sulfones has been studied and compared with heteroaryl benzothiazol-2-yl (BT), 1-phenyl-1H-tetrazol-5-yl (PT), and 1-tert-butyl-1H-tetrazol-5-yl (TBT) sulfones 9-11 under different reaction conditions. The Julia-Kocienski olefination between alkyl BTFP sulfones 7 and a wide variety of aldehydes affords the corresponding 1,2-disubstituted alkenes and dienes in good yields and stereoselectivities. This one-pot protocol can be performed using KOH at room temperature or the phosphazene bases P2-Et and P4-t-Bu at -78 °C or rt and has been successfully used in a high-yielding and stereoselective synthesis of various methoxylated stilbenes such as trimethylated resveratrol. These new reaction conditions for the Julia-Kocienski olefination reaction have been also studied with BT, PT, and TBT sulfones, giving poorer results. Methylenation of aliphatic and aromatic aldehydes, ketones, and 1,2-dicarbonyl compounds is carried out through the modified Julia olefination using BTFP methyl sulfone 7d to give terminal alkenes and dienes. Mechanistic studies of the olefination reaction between benzyl BTFP sulfone 7a and aromatic aldehydes performed by KOH-induced Smiles rearrangement of stereodefined syn- and anit-β-hydroxyalkyl BTFP sulfones indicate that the stereocontrol of the reaction is determined in the elimination step. 2005 American Chemical Society.
- Alonso, Diego A.,Fuensanta, Monica,Najera, Carmen,Varea, Montserrat
-
p. 6404 - 6416
(2007/10/03)
-
- Synthesis of methylated resveratrol and analogues by Heck reactions in organic and aqueous solvents
-
The Heck reaction under phosphane free conditions using oxime-derived palladacycles or Pd(OAc)2 as catalysts is a general methodology for the synthesis of methoxylated (E)-stilbene derivatives. Couplings can be performed either with (dicyclohexyl)methylamine as base and TBAB in aqueous DMA or in neat water and with Et3N as base in DMA in air and under thermal and microwave conditions. The arylation of different styrenes are performed with 3,5-dimethoxyiodobenzene to afford a series of important biologically active (E)-stilbene derivatives containing the 3,5-dimethoxyphenyl moiety, including resveratrol, piceatannol and pinosilvine, which are efficiently prepared with high regioselectivity and total stereoselectivity (TON up to 104).
- Botella, Luis,Nájera, Carmen
-
p. 5563 - 5570
(2007/10/03)
-
- Diethylaluminum chloride mediated vinylsilane synthesis: Comparison of different solvent systems
-
Aromatic ketones were converted to one-carbon elongated-vinylsilanes in a convenient one-pot operation via the Peterson protocol. Reactions were conducted in two different solvents for comparison: pentane and triethylamine. Results indicate that triethylamine appeared to be a more suitable solvent for such a transformation producing vinylsilanes with great chemo- and stereo-selectivity than pentane.
- Kwan, Man Lung,Battiste, Merle A.,Macala, Megan K.,Aybar, Sylvia C.,James, Nicholas C.,Haoui, Joseph J.
-
p. 1943 - 1950
(2007/10/03)
-
- A convenient one-pot, organoaluminum mediated vinylsilane synthesis from non-enolizable ketones via the Peterson protocol
-
Vinylsilanes serve as convenient vinyl anion equivalents which have gained popularity over decades. A variety of non-enolizable aromatic ketones are converted to the corresponding vinylsilanes in a one-pot procedure involving the addition of (trimethylsilylmethyl)lithium to aromatic ketones followed by addition of diethylaluminum chloride and then small amounts of water. Halide and alkoxide substituents are tolerated, and this trans-stereoselective (broad generalization; the most sterically bulky group on the double bond is trans to the trimethylsilyl group) reaction affords vinylsilanes in good yield.
- Kwan, Man Lung,Battiste, Merle A
-
p. 8765 - 8768
(2007/10/03)
-
- Substituent effects in solvolysis of 1,1-diphenylethyl p-nitrobenzoates. Symmetrically disubstituted and monosubstituted systems
-
The rates of solvolysis of 1,1-diarylethyl p-nitrobenzoates and chlorides were determined conductimetrically at 25 °C in 80% (v/v) aqueous acetone. Applying the Yukawa-Tsuno (Y-T) equation, the symmetrical (X = Y) subseries gave a precise additivity relationship for the whole substituent range with a rsym value of -3.78 and an rsym value of 0.77. While any Y subsets gave statistically less reliable Y-T correlations, the apparent ρ value changed significantly depending on the fixed Y substituents; the ρ value decreases with the more electron-donating fixed substituents Y, which is compatible with the Hammond shift of the transition state coordinate. Nevertheless, the concave correlations of the More O'Ferrall non-linearity relationship for any Y subsets are not in line with what is expected from the reactivity-selectivity relationship suggesting an anti-Hammond shift of transition state. However, we found a precise extended Bronsted relationship between the pKR+ values of 1,1-diarylethylenes and solvolysis rate process with a constant slope of α = 1.03 ± 0.03. This is direct evidence indicating that there is no significant shift of the transition-state coordinate over the whole range of substituent change. Copyright
- Fujio, Mizue,Uddin, Md. Khabir,Kim, Hyun-Joong,Tsuno, Yuho
-
p. 544 - 549
(2007/10/03)
-
- Aluminum (III) chloride - Catalyzed reaction of 1,1,1-trichloroethane with aromatic compounds: A facile synthesis of symmetrical 1,1-diphenylethylenes
-
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
-
p. 954 - 957
(2007/10/03)
-
- Electrochemical reduction and oxidation of DDT
-
Electrolysis has been studied as a possible method to treat DDT wastes. In methanol, the major process was dehydrochlorination to DDE followed by further reduction. In an aqueous emulsion containing 1% heptane and 0.1% Triton SP-175, DDT was reduced at a deposited lead electrode with sodium sulphate as the supporting electrolyte by sequential hydrodechlorination of the aliphatic chlorine atoms. An excellent material balance was achieved, but the current efficiency was poor, even at low current densities. Electrooxidation of DDT was also investigated; in aqueous solutions or emulsion, little oxidation occurred because of competing oxidation of water at the highly positive potentials needed to oxidize DDT. In acetonitrile, electrooxidation occurred with high current efficiency by way of 'electrochemical combustion' of DDT and its intermediate oxidation products to CO2. We conclude that development of an electrolytic technology for destroying DDT wastes is unlikely.
- Merica, Simona G.,Jedral, Wojceich,Lait, Susan,Keech, Peter,Bunce, Nigel J.
-
p. 1281 - 1287
(2007/10/03)
-
- Unexpected side products in the tetramethylammonium fluoride-dimethylsulphoxide system
-
Reactions of chloro- and nitro-aromatics with low water content solutions of TMAF in DMSO can lead to complex product mixtures resulting from activation of DMSO by fluoride and the formation of DMSO-derived products. Also, the system has been shown to give hydrolysis products in addition to the well-known ethers and phenols, with carboxylic acids and benzamides being formed from the attempted fluorodenitration of substituted benzonitriles.
- Adams, Dave J.,Clark, James H.,McFarland, Heather,Nightingale, David J.
-
-
- Activation conditions play a key role in the activity of zeolite CaY: NMR and product studies of Bronsted acidity
-
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
-
p. 5627 - 5638
(2007/10/03)
-
- Synthesis and double olefin extrusion of 2,2,6,6-tetraaryl-1,5-dioxa-4λ5-phosphaspiro[3.3]heptanes
-
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
-
p. 379 - 386
(2007/10/03)
-
- Substituted heterocyclylisoquinolinium salts and compositions and method of use thereof
-
Substitutued heterocyclylisoquinolinium salts, pharmaceutical compositions containing them and methods for the treatment or prevention of neurodegenerative disorders or neurotoxic injuries utilizing them.
- -
-
-
- Substituted 6,11-ethano-6,11-dihydrobenzo[b] quinolizinium salts and compositions and methods of use thereof
-
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.
- -
-
-
- Discovery of 6,11-ethano-12,12-diaryl-6,11-dihydrobenzo[b]quinolizinium cations, a novel class of N-methyl-D-aspartate antagonists
-
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
-
-