- 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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- 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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p. 334 - 345
(2020/03/10)
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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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- 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 0041-0050; 0056
(2019/07/04)
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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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- 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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- 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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- 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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- 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 0058-0061
(2017/08/24)
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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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- 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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- 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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- 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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- 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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- 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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- 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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- Synthesis of highly substituted isocoumarins by rhodium-catalyzed annulation of readily available benzoic acids
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Readily available benzoic acids possessing a number of oxygen-containing group(s) efficiently undergo oxidative coupling with alkynes through regioselective C-H bond cleavage under rhodium catalysis to form highly substituted isocoumarin derivatives. Such isocoumarins are of considerable interest due to their unique biological properties.
- Unoh, Yuto,Hirano, Koji,Satoh, Tetsuya,Miura, Masahiro
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p. 4454 - 4458
(2013/06/26)
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- Regioselective synthesis of isocoumarins by ruthenium-catalyzed aerobic oxidative cyclization of aromatic acids with alkynes
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The highly regioselective aerobic oxidative cyclization of aromatic, heteroaromatic and alkenyl acids with alkynes in the presence of catalytic amounts of [{RuCl2(p-cymene)}2], AgSbF6 and Cu(OAc)2·H2O
- Chinnagolla, Ravi Kiran,Jeganmohan, Masilamani
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supporting information; experimental part
p. 2030 - 2032
(2012/03/11)
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