- Photoredox-Catalyzed α-Aminomethyl Carboxylation of Styrenes with Sodium Glycinates: Synthesis of γ-Amino Acids and γ-Lactams
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A visible-light photoredox-catalyzed reductive α-aminomethyl carboxylation of styrenes with sodium glycinates and CO2 has been developed to synthesize a series of α,α-disubstituted γ-amino acids and γ-lactams with high efficiency and regioselectivity. Notably, CO2 released from the decarboxylation step can be reused for the subsequent carboxylation. Distinct from the previous reactions with the same type of substrates leading to simple decarboxylation and olefin hydroalkylation, this process involves additional CO2 sequestration, thus leading to olefin α-aminomethyl carboxylation. These findings not only provide new access to α,α-disubstituted γ-amino acids and γ-lactams but also serve as a proof of concept for CO2 reutilization in decarboxylation reactions.
- Zhou, Cong,Li, Miao,Sun, Jianwei,Cheng, Jiang,Sun, Song
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supporting information
p. 2895 - 2899
(2021/05/05)
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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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- 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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- 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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- Deaminative carbonylative coupling of alkylamines with styrenes under transition-metal-free conditions
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A transition-metal-free deaminative carbonylation of alkylamines with styrenes has been developed. The reaction shows good functional group compatibility and various α,β-unsaturated ketones were obtained in moderate to good yields. The alkyl radical generated from Katritzky salts via base-promoted C-N bond cleavage is one of the key intermediates in this reaction. This journal is
- Zhao, Fengqian,Li, Chong-Liang,Wu, Xiao-Feng
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supporting information
p. 9182 - 9185
(2020/08/26)
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- Bimolecular vinylation of arenes by vinyl cations
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Styrene derivatives can be easily synthesized from vinyl triflates and arenes under mild reaction conditions, using [Li][Al(OC(CF3)3)4] as a catalyst and LiHMDS as a base. This transformation is likely to involve a vinyl cation intermediate as an electrophile, which is corroborated by DFT calculations, deuterium-labeling and other control experiments. The use of an inert weakly coordinating anion is a decisive factor in this bimolecular vinylation process. This journal is
- Bour, Christophe,Gandon, Vincent,Li, Zhilong
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supporting information
p. 6507 - 6510
(2020/07/02)
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- Bisoxazoline-pincer ligated cobalt-catalyzed hydrogenation of alkenes
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The efficient and atom economical hydrogenation of alkenes using a novel bisoxazoline ligated cobalt complex has been developed. The hydrogenation of a variety of alkenes containing electron neutral and electron-donating groups proceeds in high yield, whi
- Ritz, Mikhaila D.,Parsons, Astrid M.,Palermo, Philip N.,Jones, William D.
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supporting information
(2020/02/13)
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- Overcoming Scope Limitations in Cross-Coupling of Diazo Nucleophiles by Manipulating Catalyst Speciation and Using Flow Diazo Generation
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The accessible scope of palladium-catalyzed diazo cross-coupling reactions has been expanded to include aryl chlorides by controlled diazo slow addition. The success of this strategy is based on manipulating speciation within the catalytic cycle through starvation of the diazo reagent to make the Pd(II) oxidative intermediate the resting state. The strategy is also applicable to cross-coupling reactions with aryl bromides and, in combination with safe, on-demand flow generation of nonstabilized diazo reagents, has been used to greatly expand the scope of applicable diazo compounds for this chemistry as well. Lastly, DFT calculations have provided insight into the mechanism and support for the proposed explanation for success of the slow addition strategy.
- Sullivan, Ryan J.,Freure, Garrett P.R.,Newman, Stephen G.
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p. 5623 - 5630
(2019/06/05)
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- Single-pot access to bisorganoborinates: Applications in zweifel olefination
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Zweifel olefination is a catalyst-free reaction that serves alkene functionalization. While most methods employ commercially available boron pinacol esters, we have assembled a sequence in which the two partners of the formal coupling reaction are installed successively, starting from inexpensive boron alkoxides. The in situ formation of bisorganoborinates was accomplished by consecutive reaction of two different organometallic species. This single-pot procedure represents a great advancement in the generation of organoborinates and their involvement in C-C bond formation.
- Music, Arif,Baumann, Andreas N.,Spie?, Philipp,Hilgert, Nicolas,K?llen, Martin,Didier, Dorian
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supporting information
p. 2189 - 2193
(2019/04/10)
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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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- Oxidative [4+2] Cycloaddition of α-(N-Arylamino) Carbonyls with Aryl Alkenes by Multiple C-H Functionalizations and [1,2]-Aryl Shifts
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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
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supporting information
p. 6285 - 6288
(2019/09/06)
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- Dehydrative Cross-Coupling of 1-Phenylethanol Catalysed by Palladium Nanoparticles Formed in situ under Acidic Conditions
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A dehydrative cross-coupling of 1-phenylethanol catalysed by sugar derived, in situ formed palladium(0) nanoparticles under acidic conditions is realised. The acidic conditions allow for use of alcohols as a feedstock in metal-mediated coupling reactions via their in situ dehydration and subsequent cross-coupling. Extensive analysis of the size and morphology of the palladium nanoparticles formed in situ showed that the zero-valent metal was surrounded by hydrophilic hydroxyl groups. EDX-TEM imaging studies using a prototype silicon drift detector provided insight into the problematic role of molecular oxygen in the system. This increased understanding of the catalyst deactivation allowed for the development of the cross-coupling methodology. A 250-12,000 fold increase in molar efficiency was observed when compared to related two-step protocols that use alternative feedstocks for the palladium-mediated synthesis of stilbenes. This work opens up a new research area in which the active catalyst is formed, stabilised and regenerated by a renewable sugar.
- Camp, Jason E.,Bousfield, Thomas W.,Dunsford, Jay J.,Adams, James,Britton, Joshua,Fay, Michael W.,Angelis-Dimakis, Athanasios
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supporting information
p. 3862 - 3874
(2018/09/29)
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- Electrochemically Enabled Carbohydroxylation of Alkenes with H2O and Organotrifluoroborates
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Unprecedented hydroxy-alkynylation and -alkenylation reactions of arylalkenes have been developed through electrochemically enabled addition of an organotrifluoroborate reagent and H2O across the double bond of the alkene. The use of electrochemistry to promote these oxidative alkene 1,2-difunctionalization reactions not only obviates the need for transition-metal catalysts and oxidizing reagents but also ensures high regio- and chemoselectivity to afford homopropargylic or homoallylic alcohols. The possibility of extending the electrochemical alkene difunctionalization strategy to other alkene carbo-heterofunctionalization reactions has been demonstrated.
- Xiong, Peng,Long, Hao,Song, Jinshuai,Wang, Yaohui,Li, Jian-Feng,Xu, Hai-Chao
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supporting information
p. 16387 - 16391
(2018/11/23)
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- Synthetic method of 1,1-diarylethenes derivative
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The invention discloses a synthetic method of a 1,1-diarylethenes derivative. The synthetic method comprises the following steps: with cinnamic acid derivatives and aryltriethoxysilane as raw materials, mixing the raw materials with a catalyst, an oxidizing agent, a ligand, an additive and alkali; carrying out reaction for 2 to 24 hours at 100 to 160 DEG C under argon protection in a reaction solvent so as to prepare a target compound. Because cinnamic acid is common unsaturated carboxylic acid, the preparation is convenient, cinnamic acid is cheap and easy to obtain; because aryltriethoxysilane is common organosilane in organic chemistry, aryltriethoxysilane is cheap and easy to obtain, is higher in stability and has little impact on an environment; therefore, the 1,1-diarylethenes derivative is synthesized by carrying out coupled reaction between the selected aryltriethoxysilane and the cinnamic acid derivatives. The synthetic method has the advantages of cheap and easy availabilityof the raw materials and low production cost; meanwhile, an experiment is easy to operate, and the synthetic method can be developed as an industrialized production method. According to the syntheticmethod disclosed by the invention, synthetic conditions are also screened and optimized, so that the reaction yield is further improved.
- -
-
Paragraph 0146; 0148; 0151; 0154; 0157; 0158
(2018/10/11)
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- Nickel-Catalyzed Direct Synthesis of Aryl Olefins from Ketones and Organoboron Reagents under Neutral Conditions
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Nickel-catalyzed addition of arylboron reagents to ketones results in aryl olefins directly. The neutral condition allows acidic protons of alcohols, phenols, and malonates to be present, and fragile structures are also tolerated.
- Lei, Chuanhu,Yip, Yong Jie,Zhou, Jianrong Steve
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supporting information
p. 6086 - 6089
(2017/05/08)
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- Mn(OAc)3-Mediated Synthesis of 3-Phosphonyldihydrofurans from β-Ketophosphonates and Alkenes
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A new, general method for the synthesis of 3-phosphonyldihydrofuran derivatives has been achieved through Mn(OAc)3-mediated radical cyclization between β-ketophosphonates and alkenes. This transformation allows the direct formation of C-C/C-O bonds and the construction of a dihydrofuran ring in one reaction with operational simplicity and excellent functional-group compatibility.
- Lu, Guozhang,Lin, Binzhou,Gao, Yuzhen,Ying, Jianxi,Tang, Guo,Zhao, Yufen
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p. 724 - 728
(2017/03/21)
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- Branched Arylalkenes from Cinnamates: Selectivity Inversion in Heck Reactions by Carboxylates as Deciduous Directing Groups
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A decarboxylative Mizoroki–Heck coupling of aryl halides with cinnamic acids has been developed in which the carboxylate group directs the arylation into its β-position before being tracelessly removed through protodecarboxylation. In the presence of a copper/palladium catalyst, both electron-rich and electron-deficient aryl bromides and chlorides bearing numerous functionalities were successfully coupled with broadly available cinnamates, with selective formation of 1,1-disubstituted alkenes. This reaction concept, in which the carboxylate acts as a deciduous directing group, ideally complements traditional 1,2-selective Heck reactions of styrenes.
- Tang, Jie,Hackenberger, Dagmar,Goossen, Lukas J.
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supporting information
p. 11296 - 11299
(2016/10/13)
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- Highly Chemo-, Regio-, and Stereoselective Cobalt-Catalyzed Markovnikov Hydrosilylation of Alkynes
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A highly chemo-, regio- and stereoselective cobalt-catalyzed Markovnikov hydrosilylation of alkynes was developed. Various functionalized groups, such as halides, free alcohols, free aniline, ketones, esters, amides, and nitriles are tolerated, which may lead to further applications and late-stage derivatizations. To date, this is the most efficient cobalt catalytic system (TOF=65 520 h?1; TOF=turnover frequency) for hydrosilylation of alkynes. The Hiyama–Denmark cross-coupling reactions of vinylsilanes with aryl iodides underwent smoothly to afford 1,1-diarylethenes. A unique regioselectivity-controllable hydrosilylation/hydroboration reaction of alkynes was also described.
- Guo, Jun,Lu, Zhan
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p. 10835 - 10838
(2016/09/03)
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- AIBN-catalyzed oxidative cleavage of gem -disubstituted alkenes with O 2 as an oxidant
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A 2,2-azobis(isobutyronitrile) (AIBN) catalyzed oxidative cleavage of gem-disubstituted alkenes with molecular oxygen as the oxidant has been described. Carbonyl compounds were obtained as the desired products in high yield under mild conditions. Based on previous documents and current experimental results, a relatively reasonable mechanism is proposed.
- Wang, Guang-Zu,Li, Xing-Long,Dai, Jian-Jun,Xu, Hua-Jian
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p. 7220 - 7225
(2014/08/18)
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- Efficient synthesis of polysubstituted olefins using stable palladium nanocatalyst: Applications in synthesis of tamoxifen and isocombretastatin A4
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A phosphine-free stable palladium nanocatalyst was used for an efficient synthesis of polysubstituted olefins from N-tosylhydrazones and aryl iodides. This methodology was successfully utilized in the synthesis of biologically important tamoxifen and isocombretastatin A4. The nanocatalyst was easily recovered and reused without any apparent loss in size and catalytic activity.
- Ganapathy, Dhandapani,Sekar, Govindasamy
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supporting information
p. 3856 - 3859
(2014/08/18)
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- Selective cine substitution of 1-arylethenyl acetates with arylboron reagents and a diene/rhodium catalyst
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When the crowd says Bo: A carbon-carbon bond is selectively formed at the β position of 1- arylethenyl acetate when the alkenyl substrate is reacted with arylboronic acids in the presence of a cycloocta-1,5-diene/rhodium catalyst. The choice of the ligand is crucial for the unusual cine substitution. Copyright
- Yu, Jung-Yi,Shimizu, Ryosuke,Kuwano, Ryoichi
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supporting information; experimental part
p. 6396 - 6399
(2010/11/17)
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- Thermodynamically- and kinetically-controlled Friedel-Crafts alkenylation of arenes with alkynes using an acidic fluoroantimonate(v) ionic liquid as catalyst
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By employing superacidic fluoroantimonate ionic liquid (IL), [bmim][Sb 2F11], as catalyst, not only thermodynamically-controlled but also kinetically-controlled Friedel-Crafts alkenylations of arenes with alkynes have been realized for the first time. The Royal Society of Chemistry.
- Choi, Doo Seong,Kim, Jin Hong,Shin, Ueon Sang,Deshmukh, Ravindra R.,Song, Choong Eui
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p. 3482 - 3484
(2008/03/12)
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- Decarbonylative Heck olefination of enol esters: Salt-free and environmentally friendly access to vinyl arenes
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Thank you, no salt on the side. In this variant of the Heck olefination, enol esters serve as environmentally friendly synthetic equivalents of aryl halides. These reactants, in turn, are available from a waste-free synthesis from carboxylic acids and propyne. Thus, a salt-free overall process has been devised for preparing vinyl arenes from a variety of aromatic carboxylic acids.
- Goossen, Lukas J.,Paetzold, Jens
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p. 1095 - 1098
(2007/10/03)
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- Synthesis of polysubstituted alkenes by Heck vinylation or Suzuki cross-coupling reactions in the presence of a tetraphosphane-palladium catalyst
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Through the use of [PdCl(C3H5)]2/cis,cis,cis-1,2,3, 4-tetrakis[(diphenylphosphanyl)methyl]cyclopentane as a catalyst, a range of vinyl bromides undergo Suzuki cross-couplings with arylboronic acids in good yields. Furthermore, the catalyst can be used at low loadings, even for reactions of sterically hindered substrates. Mediated by this catalyst, stilbene and 1,1-diphenylethylene undergo Heck reactions with aryl halides to give triarylethylene derivatives. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
- Berthiol, Florian,Doucet, Henri,Santelli, Maurice
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p. 1091 - 1096
(2007/10/03)
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- A new cine-substitution of alkenyl sulfones with aryltitanium reagents catalyzed by rhodium: Mechanistic studies and catalytic asymmetric synthesis of allylarenes
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The reaction of alkenyl sulfones with aryltitanium triisopropoxide (ArTi(OPr-i )3) in the presence of 3 mol % of [Rh(OH)((S)-binap)]2 in THF at 40 °C gave high yield of cine-substitution products. The catalytic cycle was established by deuterium-labeling studies, and it was applied to catalytic asymmetric synthesis of allylarenes which proceeds with over 99% enantioselectivity. Copyright
- Yoshida, Kazuhiro,Hayashi, Tamio
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p. 2872 - 2873
(2007/10/03)
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- Alkenyldimethyl(2-thienyl)silanes, excellent coupling partner for the palladium-catalyzed cross-coupling reaction
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Introduction of a 2-thienyl group to the silicon atom of alkenylsilanes promoted the cross-coupling reaction with aryl halides mediated by tetrabutylammonium fluoride and a palladium catalyst. The reaction proceeded under extremely mild conditions to affo
- Hosoi, Kazushi,Nozaki, Kyoko,Hiyama, Tamejiro
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p. 138 - 139
(2007/10/03)
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- Pd-catalyzed decarbonylative olefination of aryl esters: Towards a waste-free Heck reaction
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Easy and clean: A palladium (0)-catalyzed decarbonylative Heck olefination of activated esters of aryl, heteroaryl, and vinyl carboxylic acids opens up an opportunity for a novel waste-free Heck olefination process (see scheme).
- Goossen, Lukas J.,Paetzold
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p. 1237 - 1241
(2007/10/03)
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- Heck reaction catalyzed by phospha-palladacycles in non-aqueous ionic liquids
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Phospha-palladacycles are among the most powerful palladium catalyst systems for the Heck reaction. We have shown the use of non-aqueous ionic liquids (NAILs) as an alternative to traditional molecular solvents for this reaction, with the phospha-palladacycle catalysts resulting in easy product separation, possible catalyst recycling and further increases in catalyst productivity. Preliminary results obtained with bromo- and chloro arenes are presented.
- Herrmann, Wolfgang A.,Boehm, Volker P.W.
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p. 141 - 145
(2007/10/03)
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- On the regioselectivity of palladium catalyzed cross-coupling reactions of alkenylsilanes: participation of β-cationic organosilicate-palladium species during the transmetallation
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The cross-coupling reaction promoted by a palladium catalyst and fluoride salt of 1--1-phenylethene (1) with substituted aryl iodides gave the unexpected cine-substitution products (E)-1-aryl-2-phenylethenes (3) along with the normal ipso-substitution product 1-aryl-1-phenylethene (2).The product ratios were strongly dependent on the electronic nature of the substituent on aryl iodides: ipso-substitution products (2) were favoured by an electron-withdrawing substituent, and cine-substitution products (3) by an electron-donating substituent.On the basis of these observations, the following mechanism of transmetallation of alkenyl(fluoro)silicates with arylpalladium is proposed: electrophilic attack of an arylpalladium complex on the olefinic α-carbon of an alkenyl(fluoro)silicate produces a β-cationic organosilicate-palladium species which then transfers the alkenyl group from silicon to the palladium complex. Key words: Silane; Palladium; Transmetallation; Regioselectivity
- Hatanaka, Yasuo,Goda, Ken-ichi,Hiyama, Tamejiro
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