論文 - 河内　卓彌

Synthesis of N-Arylpyrazoles by Palladium-Catalyzed Coupling of Aryl Triflates with Pyrazole Derivatives

Onodera S., Kochi T., Kakiuchi F.

Journal of Organic Chemistry （Journal of Organic Chemistry）  84 （ 10 ） 6508 - 6515 2019年05月

ISSN  00223263

　概要を見る

© 2019 American Chemical Society. A method for the synthesis of N-arylpyrazoles by palladium-catalyzed coupling of aryl triflates with pyrazole derivatives is described. Using tBuBrettPhos as a ligand, the palladium-catalyzed C-N coupling of a variety of aryl triflates including ortho-substituted ones with pyrazole derivatives proceeded efficiently to give N-arylpyrazole products in high yields. 3-Trimethylsilylpyrazole was found to be an excellent pyrazole substrate for the coupling, and the corresponding product, 1-aryl-3-trimethylsilylpyrazole, also served as a great template for the syntheses of N-arylpyrazole derivatives, as demonstrated by regioselective halogenation at the 3-, 4-, and 5-positions of the pyrazole ring.

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Metal-Catalyzed Sequential Formation of Distant Bonds in Organic Molecules: Palladium-Catalyzed Hydrosilylation/Cyclization of 1,n-Dienes by Chain Walking

Kochi T., Ichinose K., Shigekane M., Hamasaki T., Kakiuchi F.

Angewandte Chemie - International Edition （Angewandte Chemie - International Edition）  58 （ 16 ） 5261 - 5265 2019年04月

ISSN  14337851

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© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Sequential formation of distant bonds in organic molecules was achieved for the palladium-catalyzed hydrosilylation/cyclization of various 1,n-dienes by chain walking of the metal catalyst. The reaction was applicable to various 1,n-dienes, including a 1,13-diene, to form a cyclopentane ring as well as a carbon–silicon bond at a remote site. The use of “nondissociative” chain walking provides a fascinating strategy in organic synthesis to functionalize distant parts of organic molecules, in a particular order, within a catalytic cycle by effectively moving the reactive center from a remote position.

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Selective Long-Distance Isomerization of Terminal Alkenes via Nondissociative Chain Walking

Yamasaki Y., Kumagai T., Kanno S., Kakiuchi F., Kochi T.

Journal of Organic Chemistry （Journal of Organic Chemistry）  83 （ 16 ） 9322 - 9333 2018年08月

ISSN  00223263

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© 2018 American Chemical Society. Selective long-distance isomerization of terminal alkenes to silyl enol ethers proceeded via nondissociative chain walking using phenanthroline palladium catalysts. Notable features achieved taking advantage of the nondissociative chain walking mechanism include high efficiency obtained regardless of the chain length, high chemoselectivity toward terminal alkenes over internal ones, and retention of the stereoconfiguration of the stereocenter on the alkyl chain.

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Direct Alkenylation of Allylbenzenes via Chelation-Assisted C-C Bond Cleavage

Onodera S., Ishikawa S., Kochi T., Kakiuchi F.

Journal of the American Chemical Society （Journal of the American Chemical Society）  140 （ 31 ） 9788 - 9792 2018年08月

ISSN  00027863

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© 2018 American Chemical Society. A novel method for direct transformation of allyl groups in allylbenzene derivatives to alkenyl groups via rhodium-catalyzed C-C bond cleavage is reported. The alkenylation with styrenes of allylbenzenes containing pyridyl and pyrazolyl groups as a directing group proceeded efficiently to give alkenylation products. We also developed a new protocol for transformation of an ortho-prenylated phenol to an aniline derivative.

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Palladium-Catalyzed C−H Iodination of N-(8-Quinolinyl)benzamide Derivatives Under Electrochemical and Non-Electrochemical Conditions

Sano K., Kimura N., Kochi T., Kakiuchi F.

Asian Journal of Organic Chemistry （Asian Journal of Organic Chemistry）  7 （ 7 ） 1311 - 1314 2018年07月

ISSN  21935807

　概要を見る

© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Palladium-catalyzed ortho-selective C−H iodination of N-(8-quinolinyl)benzamides proceeded using I2 under both electrochemical and non-electrochemical conditions. The C−H iodination at 90 °C under base-free conditions provided high yields of the iodination products. The use of anodic oxidation increased the efficiency of the iodination at sterically-hindered positions.

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Iron-Catalyzed Regioselective Anti-Markovnikov Addition of C-H Bonds in Aromatic Ketones to Alkenes

Naoki Kimura, Takuya Kochi, Fumitoshi Kakiuchi

J. Am. Chem. Soc. 139 （ 42 ） 14849 - 14852 2017年10月

研究論文（学術雑誌）, 共著, 査読有り

Synthesis of Fluorine-Containing Tetraarylanthracenes via Ruthenium-Catalyzed C-O or C-F Arylation and Their Crystal Structures

Akiko Izumoto, Hikaru Kondo, Takuya Kochi, Fumitoshi Kakiuchi

Synlett 28 （ 19 ） 2609 - 2613 2017年11月

研究論文（学術雑誌）, 共著, 査読有り

Formation of α-Monosubstituted Propargylamines from Terminal Alkynes and Secondary Amines Using a (PNO)Rh/Cu Tandem Catalyst System

Shotaro Takano, Takuya Kochi, Fumitoshi Kakiuchi

Chem. Lett. （Chemical Society of Japan）  46 （ 11 ） 1620 - 1623 2017年09月

研究論文（学術雑誌）, 共著, 査読有り,  ISSN  1348-0715

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A novel (PNO)Rh/CuBr (PNO: phosphine-quinolinolate) tandem catalyst system was developed for facile synthesis of α-monosubstituted propargylamines from aliphatic terminal al-kynes and secondary amines. Various terminal alkynes and amines were applicable to this reaction and the corresponding propargylamines were obtained in good yields.

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Palladium-Catalyzed Ortho-Selective C-H Chlorination of Benzamide Derivatives under Anodic Oxidation Conditions

Miki Konishi, Kazuya Tsuchida, Katsuya Sano, Takuya Kochi, Fumitoshi Kakiuchi

J. Org. Chem. 82 （ 16 ） 8716 - 8724 2017年07月

研究論文（学術雑誌）, 共著, 査読有り

Synthesis of Dibenzo[h,rst]pentaphenes and Dibenzo[fg,qr]pentacenes by the Chemoselective C–O Arylation of Dimethoxyanthraquinones

Yusuke Suzuki, Kohei Yamada, Kentaro Watanabe, Takuya Kochi, Yutaka Ie, Yoshio Aso, Fumitoshi Kakiuchi

Org. Lett. 19 （ 14 ） 3791 - 3794 2017年07月

研究論文（学術雑誌）, 共著, 査読有り

Ruthenium-Catalyzed Ortho C–H Arylation of Aromatic Nitriles with Arylboronates and Observation of Partial Para Arylation

Yuta Koseki, Kentaroh Kitazawa, Masashi Miyake, Takuya Kochi, Fumitoshi Kakiuchi

J. Org. Chem. 82 （ 13 ） 6503 - 6510 2016年12月

研究論文（学術雑誌）, 共著, 査読有り

Selective Monoarylation of Aromatic Ketones and Esters via Cleavage of Aromatic Carbon–Heteroatom Bonds by Trialkylphosphine Ruthenium Catalysts

Hikaru Kondo, Takuya Kochi, Fumitoshi Kakiuchi

Org. Lett. 19 （ 4 ） 794 - 797 2017年02月

研究論文（学術雑誌）, 共著, 査読有り

Syntheses of RuHCl(CO)(PAr3)3 and RuH2(CO)(PAr3)3 Containing Various Triarylphosphines and Their Use for Arylation of Sterically Congested Aromatic C–H Bonds

Yohei Ogiwara, Masashi Miyake, Takuya Kochi, Fumitoshi Kakiuchi

Organometallics （American Chemical Society）  36 （ 1 ） 159 - 164 2016年08月

研究論文（学術雑誌）, 査読有り,  ISSN  1520-6041

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A series of ruthenium complexes, RuHCl(CO)(PAr3)3 and RuH2(CO)(PAr3)3, containing various triarylphosphines were synthesized. Screening of these complexes as catalysts for direct arylation of sterically congested ortho C-H bonds of aromatic ketones improved the yields of the arylation products.

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Synthesis and reactivity of phosphine-quinolinolato rhodium complexes: Intermediacy of vinylidene and (amino)carbene complexes in the catalytic hydroamination of terminal alkynes

Shotaro Takano, Takuya Kochi, and Fumitoshi Kakiuchi

Organometallics （AMER CHEMICAL SOC）  35 （ 24 ） 4112 - 4125 2016年12月

研究論文（学術雑誌）, 共著, 査読有り,  ISSN  0276-7333

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We report here on the syntheses of rhodium(I) complexes bearing a phosphine-quinolinolate ligand and the isolation of two classes of important intermediates in the anti-Markovnikov hydroamination of terminal alkynes with secondary amines: vinylidene-bridged dirhodium complexes and (amino)carbene complexes. We first prepared various rhodium(I) complexes bearing a phosphine-quinolinolate ligand and found that some of these complexes had catalytic activity for the anti-Markovnikov hydroamination of terminal alkynes with secondary amines. The reaction of stoichiometric amounts of a (PNO)Rh complex with terminal alkynes provided vinylidene-bridged dirhodium complexes. When the resulting vinylidene complexes were reacted with secondary amines, (amino)carbene complexes were generated, which gave the hydroamination product upon heating with an additive. These results suggest that this anti-Markovnikov hydroamination catalyzed by (PNO)Rh complexes proceeds via vinylidene and (amino)carbene complexes.

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Chain-walking cycloisomerization of 1,n-dienes catalyzed by pyridine–oxazoline palladium catalysts and its application to asymmetric synthesis

Taro Hamasaki, Fumitoshi Kakiuchi, and, Takuya Kochi

Chem. Lett. （CHEMICAL SOC JAPAN）  45 （ 3 ） 297 - 299 2016年

研究論文（学術雑誌）, 共著, 査読有り,  ISSN  0366-7022

　概要を見る

Palladium catalysts possessing pyridine oxazoline ligands were found to catalyze the chain-walking cycloisomerization of 1,n-dienes to form five-membered rings and were particularly effective for the reaction of 1,14-dienes. Asymmetric synthesis of cyclopentane derivatives was also achieved for the reaction of 1,n-dienes using chiral pyridine oxazoline ligands.

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Chain walking as a strategy for carbon–carbon bond formation at unreactive sites in organic synthesis: Catalytic cycloisomerization of various 1,n-dienes

Taro Hamasaki, Yuka Aoyama, Junichi Kawasaki, Fumitoshi Kakiuchi, and, Takuya Kochi

J. Am. Chem. Soc. 137 （ 51 ） 16163-16171 2015年

研究論文（学術雑誌）, 共著, 査読有り

Catalytic formation of α-aryl ketones by C-H functionalization with cyclic alkenyl carbonates and one-pot synthesis of isocoumarins

Yusuke Hara, Shunsuke Onodera, Takuya Kochi, Fumitoshi Kakiuchi

Org. Lett. （AMER CHEMICAL SOC）  17 （ 19 ） 4850 - 4853 2015年

研究論文（学術雑誌）, 共著, 査読有り,  ISSN  1523-7060

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We report here a method for direct catalytic introduction of simple alpha-acylalkyl groups via rhodium-catalyzed C-H functionalization with cyclic alkenyl carbonates, synthetic equivalents to enolates bearing leaving groups. The reaction proceeded smoothly without using bases to give a-aryl ketones in high yields. Various nitrogen-containing aromatic rings and amide groups serve as directing groups. 3-Substituted isocoumarins can also be prepared by one-pot C-H functionalization/cyclization.

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Ruthenium-catalyzed monoalkenylation of aromatic ketones via cleavage of carbon-heteroatom bonds and its unconventional chemoselectivity

Hikaru Kondo, Nana Akiba, Takuya Kochi, Fumitoshi Kakiuchi

Angew. Chem., Int. Ed. 54 （ 32 ） 9293 - 9297 2015年

研究論文（学術雑誌）, 共著, 査読有り

Palladium-catalyzed regioselective homocoupling of arenes using anodic oxidation: formal electrolysis of aromatic carbon–hydrogen bonds

Fumito Saito, Hiroko Aiso, Takuya Kochi, Fumitoshi Kakiuchi

Organometallics （AMER CHEMICAL SOC）  33 （ 22 ） 6704 - 6707 2014年

研究論文（学術雑誌）, 共著, 査読有り,  ISSN  0276-7333

　概要を見る

Palladium-catalyzed regioselective homocoupling of arylpyridines under anodic oxidation conditions was achieved in the presence of I-2. The dimerization of meta-substituted arylpyridines proceeded selectively at less-sterically congested ortho-positions, and the selectivity is different from that reported for the palladium-catalyzed dimerization using Oxone as an oxidant. The dimerization also proceeds using catalytic amounts of both Pd(OAc)(2) and I-2 under the electrochemical reaction conditions.

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Ruthenium-catalyzed ortho-selective aromatic C-H alkenylation with alkenyl carbonates

Yohei Ogiwara, Takuya Kochi, Fumitoshi Kakiuchi

Chem. Lett. 43 （ 5 ） 667-669 2014年

研究論文（学術雑誌）, 共著, 査読有り