- Effect of Cp-Ligand Methylation on Rhodium(III)-Catalyzed Annulations of Aromatic Carboxylic Acids with Alkynes: Synthesis of Isocoumarins and PAHs for Organic Light-Emitting Devices
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An efficient protocol was developed for the synthesis of π-extended isocoumarins and polycyclic aromatic hydrocarbons based on the oxidative coupling of aromatic carboxylic acids with internal alkynes catalyzed by (cyclopentadienyl)rhodium complexes. The
- Molotkov, Alexander P.,Arsenov, Mikhail A.,Kapustin, Daniil A.,Muratov, Dmitry V.,Shepel', Nikolay E.,Fedorov, Yury V.,Smol'yakov, Alexander F.,Knyazeva, Elena I.,Lypenko, Dmitry A.,Dmitriev, Artem V.,Aleksandrov, Alexey E.,Maltsev, Eugeny I.,Loginov, Dmitry A.
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- Cyclooctadiene iridium complexes [Cp*Ir(COD)X]+ (X = Cl, Br, I): Synthesis and application for oxidative coupling of benzoic acid with alkynes
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The cyclooctadiene iridium complexes [Cp*Ir(COD)X]PF6 ([1a?c]PF6; X = Cl, Br, I) were synthesized by reactions of Cp*Ir(COD) with halogens followed by a counterion exchange. The cyclooctadiene in these complexes is a thermally labile
- Datsenko, Vera P.,Nelyubina, Yulia V.,Smol'yakov, Alexander F.,Loginov, Dmitry A.
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- Cp*IrIII-catalyzed oxidative coupling of benzoic acids with alkynes
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Cp*Ir(III) complexes have been shown to catalyze the oxidative coupling of benzoic acids with alkynes in methanol at 60 C to form a variety of isocoumarins. The use of AgOAc as an oxidant was required to facilitate significant product formation. Alkyl alkynes were shown to be more reactive substrates than aryl alkynes, and a number of functional groups were tolerated on benzoic acid. Combined mechanistic and computational studies (BP86) revealed that (1) C-H activation occurs via an acetate-assisted mechanism; (2) C-H activation is not turnover limiting; and (3) the oxidant oxidizes the reduced form of the catalyst via an Ir(I)-Ir(II)-Ir(III) sequence.
- Frasco, Daniel A.,Lilly, Cassandra P.,Boyle, Paul D.,Ison, Elon A.
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- Rhodium(III)-Catalyzed C(sp2)-H Chemoselective Annulation to O-Cyclized Isochromen-imines from Benzamides
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Through the development of ligands and reaction conditions, the Rh(III)-catalyzed selective annulation of benzamides with internal alkynes has been achieved to the formation of O-cyclized isochromen-imines. Various substituents are well-tolerated under mild reaction conditions. Density functional theory calculations indicate that silver carbonate could act as a Lewis acid to assist the ligand to improve the chemical selectivity of the reaction in a catalytic system.
- Zhang, Ping,Chang, Wenju,Kang, Yan-Shang,Zhao, Wenxuan,Cui, Pei-Pei,Liang, Yong,Sun, Wei-Yin,Lu, Yi
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- Cationic iridacarboranes [3-(arene)-3,1,2-IrC2B9H11]+ and [3-(MeCN)3-3,1,2-IrC2B9H11]+: Synthesis, reactivity, and bonding. Catalysis of oxidative coupling
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(Arene)iridacarboranes [3-(arene)-3,1,2-IrC2B9H11]+ (arene = benzene (1a), toluene (1b), o-xylene (1c), m-xylene (1d), durene (1e)) were synthesized by reaction of [(cod)IrCl]2 with Tl[Tl(η-7,8-C
- Loginov, Dmitry A.,Belova, Alena O.,Vologzhanina, Anna V.,Kudinov, Alexander R.
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- Cross-Dehydrogenative N-N Coupling of Aromatic and Aliphatic Methoxyamides with Benzotriazoles
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Nitrogen-nitrogen bond containing motifs are ubiquitous in bioactive compounds and organic materials. However, intermolecular hetero-selective N-H/N-H oxidative coupling reactions remain very challenging and largely unexplored. Here, we report an unprecedented, simple and hetero-selective cross-dehydrogenative N-N coupling of amides and benzotriazoles, utilizing only a hypervalent iodine species as the terminal oxidant. The scope and mechanistic investigations are discussed.
- Vemuri, Pooja Y.,Patureau, Frederic W.
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- Computational Characterization of the Mechanism for the Oxidative Coupling of Benzoic Acid and Alkynes by Rhodium/Copper and Rhodium/Silver Systems
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DFT calculations were applied to study the oxidative coupling between benzoic acid and 1-phenyl-1-propyne catalyzed by [CpRhCl2]2 (Cp=cyclopentadienyl) by using either Cu(OAc)2(H2O) or Ag(OAc) as the terminal ox
- Funes-Ardoiz, Ignacio,Maseras, Feliu
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- An efficient waste-free oxidative coupling via regioselective C-H bond cleavage: Rh/Cu-catalyzed reaction of benzoic acids with alkynes and acrylates under air
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Figure presented The direct oxidative coupling of benzoic acids with internal alkynes proceeds efficiently in the presence of a rhodium/copper catalyst system under air to afford the corresponding isocoumarin derivatives. The reaction forms no wastes exce
- Ueura, Kenji,Satoh, Tetsuya,Miura, Masahiro
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- Rhodacarboranes as catalysts for oxidative coupling of benzoic acid with diphenylacetylene
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Rhodacarboranes [(9-SMe2-7,8-Me2-C2B9H8)RhCl2]2, [(1-ButNH-1,7,9-C3B8H10)-RhI2]2, [(9-SMe2-7,8-C
- Loginov,Belova,Kudinov
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- μ-Borole triple-decker complexes as catalysts for oxidative coupling of benzoic acid with alkynes. Structure of a hybrid rhodacyclopentadienyl/borole triple-decker complex
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Reaction of dimethylamine adduct of 1-methyl-3-borolene with [(C2H4)2RhCl]2 gives the triple-decker complex (η-C4H4BMe)Rh(μ-η:η-C4H4BMe)Rh(η-C4H4
- Loginov, Dmitry A.,Muratov, Dmitry V.,Nelyubina, Yulia V.,Laskova, Julia,Kudinov, Alexander R.
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- Nickel-catalyzed C-F/O-H [4+2] Annulation of ortho-Fluoro Aromatic Carboxylic Acids with Alkynes
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Synthesis of 1H-isochromen-1-one derivatives through the C-F/O-H annulation of ortho-fluoro-substituted benzoic acids and alkynes catalyzed by a nickel complex is reported. The reaction involves the chelation-assisted activation of C-F bonds. The addition of a base, Mg(OtBu)2 is crucial for the reaction to proceed successfully.
- Chatani, Naoto,Matsuura, Akihisa
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supporting information
p. 1990 - 1992
(2022/01/12)
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- Selective annulation of benzamides with internal alkynes catalyzed by an electron-deficient rhodium catalyst
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An electron-deficient [CpERhCl2]2 catalyzed annulation of N-pentafluorophenylbenzamides with internal alkynes was successfully established under mild reaction conditions, with the assistance of Lewis acid silver salt. Particularly, electron-deficient benzamide substrates were smoothly transformed into the desired products in this catalytic system. The catalytic system showed a broad tolerance for different substituents on the aromatic rings or aryl, alkyl-substituted alkynes.
- Zhang, Ping,Chang, Wenju,Jiao, Hongyun,Kang, Yanshang,Zhao, Wenxuan,Cui, Peipei,Liang, Yong,Sun, Wei-Yin,Lu, Yi
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supporting information
p. 1717 - 1720
(2021/03/03)
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- Synthesis of Benzo-Fused Cyclic Compounds via Rhodium-Catalyzed Decarboxylative Coupling of Aromatic Carboxylic Acids with Alkynes
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The decarboxylative coupling of diversely substituted benzoic acids with internal alkynes proceeds smoothly in the presence of a [RhCl(cod)] 2/1,2,3,4-tetraphenyl-1,3-cyclopentadiene catalyst system to selectively produce highly substituted nap
- Inai, Yasuhito,Usuki, Yoshinosuke,Satoh, Tetsuya
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supporting information
p. 3029 - 3036
(2021/04/15)
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- Easy Access to Versatile Catalytic Systems for C?H Activation and Reductive Amination Based on Tetrahydrofluorenyl Rhodium(III) Complexes
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On the basis of the 1,2,3,4-tetrahydrofluorenyl ligand, a simple approach was developed to new effective rhodium catalysts for the construction of C?C and C?N bonds. The halide compounds [(η5-tetrahydrofluorenyl)RhX2]2 (2
- Kharitonov, Vladimir B.,Runikhina, Sofiya A.,Nelyubina, Yulia V.,Muratov, Dmitry V.,Chusov, Denis,Loginov, Dmitry A.
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supporting information
p. 10903 - 10912
(2021/06/28)
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- Ruthenium(ii)-catalyzed electrooxidative [4+2] annulation of benzylic alcohols with internal alkynes: Entry to isocoumarins
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A new ruthenium(ii)-catalyzed electrooxidative [4+2] annulation of primary benzylic alcohols with internal alkynes is described, which enables benzylic alcohols as weakly directing group precursors to access isocoumarins via multiple C-H functionalization. The reaction works well with a broad substrate scope, tolerates a wide range of functional groups, and incorporates practically the isocoumarin unit into diverse bioactive molecules. Mechanistic studies indicate that activation of aryl C(sp2)-H bonds is achieved through the generation of the active benzoyloxy-Ru(ii) intermediates via oxidation of benzylic alcohols using an electrooxidative Ru(ii) catalyst.
- Luo, Mu-Jia,Hu, Ming,Song, Ren-Jie,He, De-Liang,Li, Jin-Heng
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supporting information
p. 1124 - 1127
(2019/01/28)
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- Decarboxylative [4+2] annulation of arylglyoxylic acids with internal alkynes using the anodic ruthenium catalysis
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A new electrochemical decarboxylative [4+2] annulation of arylglyoxylic acids with internal alkynes involving C-H functionalization by means of a cooperative anode and ruthenium catalysis is presented. This reaction represents a mechanistically novel strategy as an ideal supplement to the decarboxylative [4+2] annulation methodology by employing an electrooxidative process to avoid the use of an additional external oxidizing reagent and utilizing H2O as the carboxyl oxygen atom source to be engaged in the synthesis of 1H-isochromen-1-ones.
- Luo, Mu-Jia,Zhang, Ting-Ting,Cai, Fang-Jun,Li, Jin-Heng,He, De-Liang
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supporting information
p. 7251 - 7254
(2019/07/02)
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- Cobalt(III)-Catalyzed Oxidative Annulation of Benzaldehydes with Internal Alkynes via C-H Functionalization in Poly(ethylene glycol)
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A novel Co(III)-catalyzed oxidative annulation of aromatic aldehydes with internal alkynes for accessing isocoumarins is described, which is achieved by oxidation, weak chelation-assisted C-H bond functionalization, and annulation cascades with excellent functional group compatibility, high atom economy, and step efficiency. By using environmentally benign and inexpensive poly(ethylene glycol)-400 (PEG-400), the Co/Cu/PEG-400 system could be recycled and reused.
- Tao, Li-Ming,Li, Chuan-Hua,Chen, Jun,Liu, Hui
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p. 6807 - 6812
(2019/06/14)
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- Synthesis method of isocoumarin compounds
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The invention discloses a synthesis method of isocoumarin compounds. According to the method, benzaldehyde compounds and alkyne compounds are taken as reaction materials, and the isocoumarin compoundsare prepared under the condition of a cobalt catalyst w
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Paragraph 0041-0049
(2019/07/04)
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- Rhodium(I)-Catalyzed Decarbonylative Aerobic Oxidation of Cyclic α-Diketones: A Regioselective Single Carbon Extrusion Strategy
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A rhodium-catalyzed decarbonylative aerobic oxidation of cyclic α-diketones has been developed for the first time, where the regioselective formations of α-pyrones and isocoumarins have been achieved. The current decarbonylative aerobic oxidation pathway proceeds via the C-C bond cleavage followed by a C-O bond formation, representing a biomimetic oxidation approach to unsaturated six-membered cyclic lactones. The unique ability of rhodium catalysts to induce the decarbonylative aerobic oxidation opens up a new synthetic toolbox that utilizes the "regioselective single carbon" extrusion strategy.
- Golime, Gangadhararao,Kim, Hun Young,Oh, Kyungsoo
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p. 942 - 945
(2018/02/22)
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- Room Temperature Decarboxylative and Oxidative [2+2+2] Annulation of Benzoic Acids with Alkynes Catalyzed by an Electron-Deficient Rhodium(III) Complex
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It has been established that an electron-deficient (η5-cyclopentadienyl)rhodium(III) [CpERhIII] complex is capable of catalyzing the decarboxylative and oxidative [2+2+2] annulation of benzoic acids with alkynes to produce substituted naphthalenes at room temperature. The appropriate choice of the additive and the solvent is crucial for this transformation. This catalyst system allowed use of oxygen as a terminal oxidant and broadened the substrate scope including both aromatic and aliphatic alkynes. In this catalysis, the electron deficient nature of the CpERhIII catalyst would cause the strong rhodium-π interaction, which accelerates the decarboxylation as well as the C?H bond cleavage.
- Honjo, Yusaku,Shibata, Yu,Kudo, Eiji,Namba, Tomoya,Masutomi, Koji,Tanaka, Ken
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supporting information
p. 317 - 321
(2017/11/01)
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- Rhodium(III)-Catalyzed Oxidative Annulation of Acrylic Acid with Alkynes: An Easy Approach to the Synthesis of α-Pyrones
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A highly efficient rhodium(III)-catalyzed direct oxidative annulation of acrylic acid with alkynes to form α-pyrones was developed. Various substituted acrylic acids were compatible in this transformation, affording the corresponding products in moderate to excellent yields under mild conditions.
- Li, Yu-Ting,Zhu, Yan,Tu, Guang-Liang,Zhang, Jing-Yu,Zhao, Ying-Sheng
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supporting information
p. 3281 - 3284
(2018/10/09)
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- Electrooxidative Ruthenium-Catalyzed C?H/O?H Annulation by Weak O-Coordination
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Electrocatalysis has been identified as a powerful strategy for organometallic catalysis, and yet electrocatalytic C?H activation is restricted to strongly N-coordinating directing groups. The first example of electrocatalytic C?H activation by weak O-coo
- Qiu, Youai,Tian, Cong,Massignan, Leonardo,Rogge, Torben,Ackermann, Lutz
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supporting information
p. 5818 - 5822
(2018/05/14)
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- Photopromoted Entry to Benzothiophenes, Benzoselenophenes, 3H-Indoles, Isocoumarins, Benzosultams, and (Thio)flavones by Gold-Catalyzed Arylative Heterocyclization of Alkynes
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Visible light-promoted and gold-photoredox-catalyzed reactions of heteroatom (N, S, Se, O) tethered alkynes with arenediazonium salts selectively proceeded to build vicinal diaryl-substituted 2H-benzo[e][1,2]thiazine 1,1-dioxides (benzosultams), benzoselenophenes, benzothiophenes, 4H-chromen-4-ones (flavones), 3H-indoles, 1H-isochromen-1-ones (isocoumarins), and 4H-thiochromen-4-ones (thioflavones). Moreover, the utility of functionalized 3H-indoles as precursors for further elaboration has been demonstrated with the switchable and facile preparation of 1H-indoles, 2-oxindoles, and 3-oxindolines. (Figure presented.).
- Alcaide, Benito,Almendros, Pedro,Busto, Eduardo,Herrera, Fernando,Lázaro-Milla, Carlos,Luna, Amparo
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supporting information
p. 2640 - 2652
(2017/08/16)
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- N-O Bond as External Oxidant in Group 9 Cp?M(III)-Catalyzed Oxidative C-H Coupling Reactions
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Group 9 Cp?M(III) (M = Co, Rh, Ir) complexes have been extensively investigated as catalysts in a variety of C-H activation reactions. Typically, late metal-based silver or copper salt was used (while needed) as oxidant in these catalytic systems. Herein, we report our discovery of a potentially general type of N-O bond-containing oxidants, which allowed the mild and efficient syntheses of isocoumarins, isoquinolines, isoquinolinone, and styrenes via C-H activation catalyzed by group 9 Cp?M(III) complexes. By using Cp?Rh(III)-catalyzed isocoumarin synthesis as a model reaction, experimental and theoretical mechanistic studies were conducted. The results concluded that the Rh(III)-Rh(I)-Rh(III) rather than the Rh(III)-Rh(V)-Rh(III) pathway is more likely involved in the mechanism, and both the C-H activation and oxidation of the Cp?Rh(I) species were involved in the turnover-limiting step.
- Liu, Xu-Ge,Gao, Hui,Zhang, Shang-Shi,Li, Qingjiang,Wang, Honggen
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p. 5078 - 5086
(2017/08/17)
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- One-Pot Sequential N-Heterocyclic Carbene/Rhodium(III) Catalysis: Synthesis of Fused Polycyclic Isocoumarins
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A one-pot sequential N-heterocyclic carbene–rhodium (NHC-Rh) catalysis is described, demonstrating the compatibility of NHC and Rh catalysts. N-Heterocyclic carbene-catalyzed aerobic oxidation of benzaldehydes and subsequent rhodium(III)-catalyzed oxidative coupling/annulation with multiple bonds enabled the formation of two C–O bonds and one C–C bond in a single pot. This operationally easy, one-pot protocol under air provides access to a diverse array of valuable fused polycyclic isocoumarins. (Figure presented.).
- Youn, So Won,Yoo, Huen Ji
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supporting information
p. 2176 - 2183
(2017/07/07)
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- Tert-Butyl Nitrite-Mediated Synthesis of N-Nitrosoamides, Carboxylic Acids, Benzocoumarins, and Isocoumarins from Amides
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This work reports tert-butyl nitrite (TBN) as a multitask reagent for (1) the controlled synthesis of N-nitrosoamide from N-alkyl amides, (2) hydrolysis of N-methoxyamides to carboxylic acids, (3) metal- and oxidant-free benzocoumarin synthesis from ortho-aryl-N-methoxyamides via N-H, C-N, and C-H bond activation, and (4) isocoumarin synthesis using Ru(II)/PEG as a recyclable catalytic system via ortho-C-H activation and TBN as an oxygen source. The sequential functional group interconversion of amide to acid has also been examined using IR spectroscopic analysis. Additionally, this methodology is highly advantageous due to short reaction time, gram scale synthesis, and broad substrate scope.
- Yedage, Subhash L.,Bhanage, Bhalchandra M.
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p. 5769 - 5781
(2017/06/07)
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- Palladium-catalyzed carbonylative synthesis of isocoumarins and phthalides by using phenyl formate as a carbon monoxide source
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A simple and efficient palladium-catalyzed intramolecular carbonylative synthesis of isocoumarins and phthalides from the easily available starting materials by employing phenyl formate as a CO surrogate has been achieved. The approach affords target compounds in good to excellent yields with the advantages of lower toxicity, milder conditions, easy operation and wide functional group tolerance.
- Yuan, Qing,Chen, Zhen-Bang,Zhang, Fang-Ling,Zhu, Yong-Ming
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p. 1628 - 1635
(2017/02/23)
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- Multi-substituted isocoumarin derivatives and its preparation method
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The invention discloses a multi-substituent isocoumarin derivative and a preparation method thereof. According to the preparation method, substituted tert-butyl peroxybenzoate represented by a formula II, 1,2-disubstituted acetylene represented by a formula III, a catalyst, alkali, acid and a solvent are uniformly mixed and are heated under the protection of nitrogen for a cyclization reaction, and a compound represented by a general structure formula I is obtained after the reaction. According to the method, the reaction conditions are mild, the reaction time is short, the substrate range is wide, the reaction specificity is high, the yield is high, the post-processing is simple and convenient, and the multi-substituent isocoumarin derivative which cannot be synthesized with other methods can be synthesized and has a wide application.
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Paragraph 0022-0025
(2017/08/24)
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- Cp?Co(III)-Catalyzed Annulation of Carboxylic Acids with Alkynes
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A new procedure for oxidative coupling of aromatic and acrylic acids with alkynes has been developed using abundant, nontoxic, and air stable Cp?Co(III) catalyst. The coupling involves initial cyclometalation via weak chelation-assisted C-H bond activation followed by alkyne coordination, insertion, and reductive elimination leading to diverse isocoumarins (α-pyranones) in good yields under mild conditions.
- Mandal, Rajib,Sundararaju, Basker
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supporting information
p. 2544 - 2547
(2017/05/25)
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- Ru(II)/PEG-400 as a highly efficient and recyclable catalytic media for annulation and olefination reactions: Via C-H bond activation
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In this report synthesis of isoquinolinones, isocoumarins, and N-methyl isoquinolinones and olefination of the Weinreb amides by C-H bond activation using Ru(ii)/PEG-400 as green and recyclable media are documented. This developed methodology is capable o
- Yedage, Subhash L.,Bhanage, Bhalchandra M.
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p. 5635 - 5642
(2016/10/21)
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- Synthesis of Phthalides through Tandem Rhodium-Catalyzed C–H Olefination and Annulation of Benzamides
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The rhodium(III)-catalyzed tandem C–H olefination and cyclization of benzamides with various alkenes is described. This protocol provides direct access to highly substituted phthalides, which are known as crucial frameworks of biologically active compounds. In particular, the amide directing group containing a benzimidazole group facilitates the activation of aromatic ortho-C–H bonds leading to olefination intermediates, and is spantaneously converted into an acid moiety, which can further undergo the intramolecular annulation process.
- Mishra, Neeraj Kumar,Park, Jihye,Choi, Miji,Sharma, Satyasheel,Jo, Hyeim,Jeong, Taejoo,Han, Sangil,Kim, Saegun,Kim, In Su
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p. 3076 - 3083
(2016/07/12)
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- Oxidative Annulation of Arenecarboxylic and Acrylic Acids with Alkynes under Ambient Conditions Catalyzed by an Electron-Deficient Rhodium(III) Complex
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It has been established that an electron-deficient CpErhodium(III) complex catalyzes the oxidative [4+2] annulation of substituted arenecarboxylic and acrylic acids with alkynes under ambient conditions (at RT–40 °C, under air) without using excess amounts of substrates to produce the corresponding substituted isocoumarins and α-pyrones in high yields. Minor modification of reaction conditions depending on the coordination ability of alkynes realized the high efficiency.
- Kudo, Eiji,Shibata, Yu,Yamazaki, Mutsumi,Masutomi, Koji,Miyauchi, Yuta,Fukui, Miho,Sugiyama, Haruki,Uekusa, Hidehiro,Satoh, Tetsuya,Miura, Masahiro,Tanaka, Ken
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supporting information
p. 14190 - 14194
(2016/09/23)
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- Rhodium(III)-Catalyzed C-H Activation/Alkyne Annulation by Weak Coordination of Peresters with O-O Bond as an Internal Oxidant
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A redox-economic strategy has been developed, involved in an efficient Rh(III)-catalyzed oxidative C-H activation and alkyne annulation with perester as the oxidizing directing group. In this process, the cleavage of an oxidizing O-O bond as an internal oxidant is described for the first time. This reaction could be carried out under mild conditions and exhibits excellent regioselectivity and wide functional groups tolerance.
- Mo, Jiayu,Wang, Lianhui,Cui, Xiuling
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supporting information
p. 4960 - 4963
(2015/11/03)
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- Ru-catalyzed decarboxylative annulations of α-keto acids with internal alkynes: Dual roles of cooh as directing group and leaving group
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Carboxylic acid serving as both directing and leaving group was discovered in Ru-catalyzed decarboxylative annulations of α-keto acids with alkynes. The wellestablished protocol showed high functional group tolerance, which provided an efficient and alter
- Tan, Hui,Li, Hongji,Wang, Jiawang,Wang, Lei
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supporting information
p. 1904 - 1907
(2015/01/30)
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- Ruthenium-catalyzed decarbonylative addition reaction of anhydrides with alkynes: A facile synthesis of isocoumarins and α-pyrones
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A novel ruthenium catalyzed straightforward and efficient synthesis of isocoumarin and α-pyrone derivatives has been accomplished by the decarbonylative addition reaction of anhydrides with alkynes under thermal conditions.
- Prakash, Rashmi,Shekarrao, Kommuri,Gogoi, Sanjib,Boruah, Romesh C.
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supporting information
p. 9972 - 9974
(2015/06/22)
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- Ruthenium(II)-catalyzed C-H activation/alkyne annulation by weak coordination with O2 as the sole oxidant
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Aerobic oxidative C-H functionalizations of weakly coordinating benzoic acids have been accomplished with versatile ruthenium(II) biscarboxylates under ambient oxygen or air. Mechanistic studies identified the key factors controlling the elementary step o
- Warratz, Svenja,Kornhaa?, Christoph,Cajaraville, Ana,Niep?tter, Benedikt,Stalke, Dietmar,Ackermann, Lutz
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supporting information
p. 5513 - 5517
(2015/04/27)
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- Palladium-catalyzed annulation of internal alkynes in aqueous medium
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To facilitate precatalyst recovery and reuse, we have developed a fluorous, oxime-based palladacycle 1 and demonstrated that it is a very efficient and versatile precatalyst for carbo- and heteroannulation of internal alkynes with functionalized aryl halides in aqueous medium. A uniform reaction condition for these annulation reactions was also developed.
- Ang, Wei Jie,Tai, Chih-Hsuan,Lo, Lee-Chiang,Lam, Yulin
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p. 4921 - 4929
(2014/01/23)
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- Palladium-Catalyzed Carbonylative Reactions of 1-Bromo-2-fluorobenzenes with Various Nucleophiles: Effective Combination of Carbonylation and Nucleophilic Substitution
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systematic study on the carbonylative transformation of 1-bromo-2-fluorobenzenes with various nucleophiles has been performed. Different types of double nucleophiles, such as N-N, N-C, O-C, and N-S, can be effectively applied as coupling partners. The cor
- Chen, Jianbin,Natte, Kishore,Neumann, Helfried,Wu, Xiao-Feng
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supporting information
p. 16107 - 16110
(2015/01/09)
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- Rhodium(III)-catalysed decarbonylative coupling of maleic anhydrides with alkynes
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A formal [5 - 1 + 2] annulation for the preparation of substituted α-pyrones is reported. The reaction involves the decarbonylative coupling of substituted maleic anhydrides with internal alkynes in the presence of a rhodium(III) catalyst and a copper(II)
- Matsuda, Takanori,Suzuki, Kentaro
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p. 37138 - 37141
(2014/11/08)
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- Rhodium(III)-catalyzed, C-H activated annulation to form isocoumarins and α-pyrones using the O-N bond as an internal oxidant
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A mild, efficient and regioselective C-H activation-based intermolecular redox-neutral annulation of O-benzoylhydroxylamines and internal alkynes has been achieved. The protocol employs an O-N bond as the internal oxidant and leads to isocoumarins and α-pyrones.
- Li, Xing Guang,Liu, Kai,Zou, Gang,Liu, Pei Nian
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p. 1496 - 1500
(2014/06/09)
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- Rhodium-catalyzed oxidative C-H activation/cyclization for the synthesis of phosphaisocoumarins and phosphorous 2-pyrones
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Rhodium-catalyzed cyclization of phosphinic acids and phosphonic monoesters with alkynes has been developed. The oxidative annulation proceeds with complete conversion of phosphinic acid derivatives and allowed the atom-economic preparation of useful phosphaisocoumarins with high yield and selectivity. The reaction is tolerant of extensive substitution on the phosphinic acid, phosphonic monoester and alkyne, including halides, ketone, and hydroxyl groups as substituents. Furthermore, we found that alkenylphosphonic monoesters proceed to give a wide range of phosphorus 2-pyrones through oxidative annulation with alkynes. Mechanistic studies revealed that Ci£H bond metalation was the rate-limiting step. Copyright
- Park, Youngchul,Seo, Jungmin,Park, Sangjune,Yoo, Eun Jeong,Lee, Phil Ho
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supporting information
p. 16461 - 16468
(2013/12/04)
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- New method for the synthesis of lactones via nickel-catalyzed isocyanides insertion
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A novel nickel catalyst for the reaction of tert-butyl isocyanide insertion was discovered. In this approach, 1,2-bis(diphenylphosphino)ethane (L3) serves as an efficient ligand, thereby allowing the preparation of lactones from (o-bromophenyl)phenylethanone derivatives. It is noteworthy that this is the first example of nickel acting as a metal catalyst in the reactions of tert-butyl isocyanide insertion. The significance of this methodology may draw many chemists attention in the field of isocyanide-incorporating reactions. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications for the following free supplemental resource(s): Full experimental and spectral details.]
- Fei, Xiang-Dong,Tang, Ting,Ge, Zhi-Yuan,Zhu, Yong-Ming
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p. 3262 - 3271
(2013/10/01)
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- Water as a green solvent for efficient synthesis of isocoumarins through microwave-accelerated and Rh/Cu-catalyzed C-H/O-H bond functionalization
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Green chemistry that uses water as a solvent has recently received great attention in organic synthesis. Here we report an efficient synthesis of biologically important isocoumarins through direct cleavage of C-H/O-H bonds by microwave-accelerated and Rh/
- Li, Qiu,Yan, Yunnan,Wang, Xiaowei,Gong, Binwei,Tang, Xiaobo,Shi, Jingjing,Xu, H. Eric,Yi, Wei
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p. 23402 - 23408
(2013/11/19)
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- Palladium-catalyzed synthesis of isocoumarins and phthalides via tert -butyl isocyanide insertion
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A novel and highly efficient strategy for the synthesis of isocoumarins and phthalides through a palladium(0)-catalyzed reaction incorporating tert-butyl isocyanide has been developed. This process, providing one of the simplest methods for the synthesis of this class of valuable lactones, involves two steps including cyclization reaction and simple acid hydrolysis. The methodology is tolerant of a wide range of substrates and applicable to library synthesis.
- Fei, Xiang-Dong,Ge, Zhi-Yuan,Tang, Ting,Zhu, Yong-Ming,Ji, Shun-Jun
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p. 10321 - 10328
(2013/01/15)
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- Synthesis of (1H)-isochromen-1-imines by nickel-catalyzed reaction of 2-iodobenzamides with alkynes
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2-Iodobenzamides reacted with alkynes in the presence of a nickel(0)/P(4-ClC6H4)3 catalyst to produce substituted (1H)-isochromen-1-imines. The reaction proceeded through the formation of an oxanickelacycle, alkyne insertion, and reductive elimination.
- Miura, Tomoya,Hiraga, Kentaro,Toyoshima, Takeharu,Yamauchi, Motoshi,Murakami, Masahiro
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p. 798 - 800
(2012/09/07)
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- Versatile synthesis of isocoumarins and α-pyrones by Ruthenium-catalyzed oxidative C - H/O - H bond cleavages
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An inexpensive cationic ruthenium(II) catalyst enabled the expedient synthesis of isocoumarins through oxidative annulations of alkynes by benzoic acids. This C - H/O - H bond functionalization process also proved applicable to the preparation of α-pyrones and was shown to proceed by rate-limiting C - H bond ruthenation.
- Ackermann, Lutz,Pospech, Jola,Graczyk, Karolina,Rauch, Karsten
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supporting information; experimental part
p. 930 - 933
(2012/03/26)
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- Rhodium-catalyzed oxidative cycloaddition of benzamides and alkynes via C-H/N-H activation
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The oxidative cycloaddition of benzamides and alkynes has been developed. The reaction utilizes Rh(III) catalysts in the presence of Cu(II) oxidants, and is proposed to proceed by N-H metalation of the amide followed by ortho C-H activation. The resultant rhodacycle undergoes alkyne insertion to form isoquinolones in good yield. The reaction is tolerant of extensive substitution on the amide, alkyne, and arene, including halides, silyl ethers, and unprotected aldehydes as substituents. Unsymmetrical alkynes proceed with excellent regioselectivity, and heteroaryl carboxamides are tolerated leading to intriguing scaffolds for medicinal chemistry. A series of competition experiments shed further light on the mechanism of the transformation and reasons for selectivity.
- Hyster, Todd K.,Rovis, Tomislav
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supporting information; experimental part
p. 10565 - 10569
(2010/09/17)
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- Rhodium- and iridium-catalyzed oxidative coupling of benzoic acids with alkynes via regioselective C-H bond cleavage
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(Chemical Equation Presented) The oxidative coupling of benzoic acids with internal alkynes effectively proceeds in the presence of [Cp*RhCl 2]2 and Cu(OAc)2·H2O as catalyst and oxidant, respectively, to produce
- Ueura, Kenji,Satoh, Tetsuya,Miura, Masahiro
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p. 5362 - 5367
(2008/02/08)
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- Synthesis of isocoumarins and α-pyrones via electrophilic cyclization
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A variety of substituted isocoumarins and α-pyrones are readily prepared in excellent yields under very mild reaction conditions by the reaction of o-(1-alkynyl)benzoates and (Z)-2-alken-4-ynoates with ICl, I2, PhSeCl, p-O2NC6/
- Yao, Tuanli,Larock, Richard C.
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p. 5936 - 5942
(2007/10/03)
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