Shinichi Saito

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Organization: Tokyo University of Science

Department: Department of Chemistry, Faculty of Science

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Organic Chemistry

Rotaxane

Chemicals
References

Synthesis of [2]Catenanes by Intramolecular Sonogashira-Type Reaction

Co-reporter:Ken Ito, Yuichiro Mutoh, and Shinichi Saito

The Journal of Organic Chemistry June 16, 2017 Volume 82(Issue 12) pp:6118-6118

Publication Date(Web):May 18, 2017

DOI:10.1021/acs.joc.7b00672

The catalytic activity of macrocyclic phenanthroline-CuI complexes was utilized to synthesize [2]catenanes by intramolecular Sonogashira-type reaction. The high reactivity of the acyclic starting material was critical to synthesize the [2]catenane in acceptable yields. The relationship between the yield of the [2]catenane and the structure of the starting materials was disclosed.

Ruthenium-Catalyzed Cycloisomerization of 2-Alkynylanilides: Synthesis of 3-Substituted Indoles by 1,2-Carbon Migration

Co-reporter:Takuma Watanabe, Yuichiro Mutoh, and Shinichi Saito

Journal of the American Chemical Society June 14, 2017 Volume 139(Issue 23) pp:7749-7749

Publication Date(Web):May 24, 2017

DOI:10.1021/jacs.7b04564

We developed ruthenium-catalyzed cycloisomerization of alkynylanilides that gave 3-substituted indoles in high yields. The reaction proceeded via the disubstituted vinylidene ruthenium complex that was formed by the 1,2-carbon migration.

Synthesis of Tricyclic Benzazocines by Aza-Prins Reaction

Co-reporter:Tomohiro Katamura, Tomoaki Shimizu, Yuichiro MutohShinichi Saito

Organic Letters 2017 Volume 19(Issue 1) pp:266-269

Publication Date(Web):December 16, 2016

DOI:10.1021/acs.orglett.6b03577

The aza-Prins reaction of 3-vinyltetrahydroquinolines with aldehydes proceeded smoothly in the presence of hydrogen halides, and the tricyclic benzazocine derivatives were isolated in good to high yields. The reaction would proceed through the formation and cyclization of the iminium ion intermediate.

A ruthenium tellurocarbonyl (CTe) complex with a cyclopentadienyl ligand: systematic studies of a series of chalcogenocarbonyl complexes [CpRuCl(CE)(H2IMes)] (E = O, S, Se, Te)

Co-reporter:Ayumi Suzuki;Takahiro Arai;Kota Ikenaga;Yuichiro Mutoh;Noriko Tsuchida;Youichi Ishii

Dalton Transactions 2017 vol. 46(Issue 1) pp:44-48

Publication Date(Web):2016/12/19

DOI:10.1039/C6DT04440A

The first tellurocarbonyl complex with a half-sandwich structure [CpRuCl(CTe)(H2IMes)] was synthesized by a ligand substitution reaction. The practically complete series of the CpCE complexes [CpRuCl(CE)(H2IMes)] (E = O, S, Se, Te) were systematically explored. The tellurium atom in the CTe complex could be smoothly replaced with lighter chalcogen atoms.

Sequence-Selective Synthesis of Rotacatenane Isomers

Co-reporter:Ryuto Hayashi, Petr Slavík, Yuichiro Mutoh, Takeshi Kasama, and Shinichi Saito

The Journal of Organic Chemistry 2016 Volume 81(Issue 3) pp:1175-1184

Publication Date(Web):January 7, 2016

DOI:10.1021/acs.joc.5b02697

Rotacatenane is an interlocked compound composed of two mechanically interlocked macrocyclic components, i.e., a [2]catenane, and one axle component. In this paper we describe the selective synthesis of isomeric rotacatenanes. Two [2]rotaxanes with different phenanthroline moieties were synthesized by the oxidative coupling of an alkyne with a bulky blocking group, which proceeded in the cavity of the macrocyclic phenanthroline–Cu complex. The metal template method was used to install another cyclic component: the tetrahedral Cu(I) complex, which was composed of a [2]rotaxane and an acyclic phenanthroline derivative, was synthesized, and the cyclization of the phenanthroline derivative gave the rotacatenane. The sequential isomers of rotacatenanes were distinguished by 1H and 13C NMR spectroscopy.

Synthesis and Shuttling Behavior of [2]Rotaxanes with a Pyrrole Moiety

Co-reporter:Yusuke Matsuoka, Yuichiro Mutoh, Isao Azumaya, Shoko Kikkawa, Takeshi Kasama, and Shinichi Saito

The Journal of Organic Chemistry 2016 Volume 81(Issue 9) pp:3479-3487

Publication Date(Web):March 7, 2016

DOI:10.1021/acs.joc.5b02911

We synthesized [2]rotaxanes with a pyrrole moiety from a [2]rotaxane with a 1,3-diynyl moiety. The conversion of the 1,3-diynyl moiety of the axle component to the pyrrole moiety was accomplished by a Cu-mediated cycloaddition of anilines. The cycloaddition reaction was accelerated when the [2]rotaxane was used as the substrate. The effect of the structure of the pyrrole moiety on the rate of the shuttling was studied.

Synthesis of [3]Rotaxanes by the Combination of Copper-Mediated Coupling Reaction and Metal-Template Approach

Co-reporter:Ryuto Hayashi, Yuichiro Mutoh, Takeshi Kasama, and Shinichi Saito

The Journal of Organic Chemistry 2015 Volume 80(Issue 15) pp:7536-7546

Publication Date(Web):July 10, 2015

DOI:10.1021/acs.joc.5b01120

[3]Rotaxanes with two axle components and one ring component were synthesized by the combination of a coupling reaction using a transition-metal catalyst and a metal-template approach. Thus, [2]rotaxanes were prepared by the oxidative dimerization of alkyne promoted by macrocyclic phenanthroline–CuI complexes. The [2]rotaxane was reacted with a CuI salt and an acyclic ligand to generate a tetrahedral CuI complex. Metal-free [3]rotaxane was isolated by the end-capping reaction of the acyclic ligand, followed by the removal of CuI ion. The stability of the tetrahedral CuI complexes depended on the size of both the ring component and the acyclic ligand, which was correlated with the yield of the corresponding [3]rotaxane.

Synthesis of [3]Rotaxanes that Utilize the Catalytic Activity of a Macrocyclic PhenanthrolineCu Complex: Remarkable Effect of the Length of the Axle Precursor

Co-reporter:Yoshiaki Yamashita;Dr. Yuichiro Mutoh;Dr. Ryu Yamasaki; Takeshi Kasama; Shinichi Saito

Chemistry - A European Journal 2015 Volume 21( Issue 5) pp:2139-2145

Publication Date(Web):

DOI:10.1002/chem.201405090

Abstract

[3]Rotaxanes, which consist of one macrocyclic phenanthroline compound and two axle components, were prepared by the oxidative dimerization of an alkyne compound with bulky tris[4′-cyclohexyl-(1,1′-biphenyl)-4-yl]methyl blocking group. The catalytic activity of a macrocyclic phenanthroline–Cu complex was utilized to thread the two axle components inside the ring. The alkyne compound with chain of 15 or 20 methylene groups gave [3]rotaxanes in high yields, whereas the axle with a chain of six methylene groups afforded a [3]rotaxane in very poor yield. We also examined the effect of the ring size on the synthesis of [3]rotaxanes. [3]Rotaxanes were not isolated when a macrocyclic phenanthroline compound with a smaller ring size was used.

Synthesis of interlocked compounds utilizing the catalytic activity of macrocyclic phenanthroline–Cu complexes

Co-reporter:Shinichi Saito

Journal of Inclusion Phenomena and Macrocyclic Chemistry 2015 Volume 82( Issue 3-4) pp:437-451

Publication Date(Web):2015 August

DOI:10.1007/s10847-015-0511-1

A new method for the synthesis of interlocked compounds utilizing the catalytic activity of macrocyclic phenanthroline–Cu complexes was developed. The macrocyclic phenanthroline–Cu complexes were found to be good catalysts for several coupling reactions, and this catalytic activity was subsequently utilized for the synthesis of [2]rotaxanes and [2]catenanes. By combining the catalytic threading approach with the well-known metal-template method, several rotacatenanes were synthesized. In addition, one-pot synthesis of [3]rotaxanes was achieved in good yield by performing the threading reaction twice in a one-ring component.

Synthesis of rotacatenanes by the combination of Cu-mediated threading reaction and the template method: the dual role of one ligand

Co-reporter:Ryuto Hayashi, Kota Wakatsuki, Ryu Yamasaki, Yuichiro Mutoh, Takeshi Kasama and Shinichi Saito

Chemical Communications 2014 vol. 50(Issue 2) pp:204-206

Publication Date(Web):24 Oct 2013

DOI:10.1039/C3CC47425A

Rotacatenanes were synthesized by the catalytic reaction using a macrocyclic phenanthroline–CuI complex followed by the installation of another ring by the template method. In this approach, the size of the ring component of the rotaxane turns out to be a very important factor for the synthesis of rotacatenanes.

Acid-Mediated Ring-Expansion Reaction of N-Aryl-2-vinylazetidines: Synthesis and Unanticipated Reactivity of Tetrahydrobenzazocines

Co-reporter:Tomoaki Shimizu, Shunsuke Koya, Ryu Yamasaki, Yuichiro Mutoh, Isao Azumaya, Kosuke Katagiri, and Shinichi Saito

The Journal of Organic Chemistry 2014 Volume 79(Issue 10) pp:4367-4377

Publication Date(Web):April 14, 2014

DOI:10.1021/jo500249c

The aza-Clasen rearrangement of N-aryl-2-vinylazetidines has been explored. N-Aryl-2-vinylazetidines were transformed to corresponding tetrahydrobenzazocines in good yields. Unexpectedly, the tetrahydrobenzazocine was unstable and readily isomerized to vinyltetrahydroquinoline in the presence of acid. The mechanism of this ring contraction was studied in detail.

Synthesis of [2]Rotaxanes by the Copper-Mediated Threading Reactions of Aryl Iodides with Alkynes

Co-reporter:Kenta Ugajin, Eiko Takahashi, Ryu Yamasaki, Yuichiro Mutoh, Takeshi Kasama, and Shinichi Saito

Organic Letters 2013 Volume 15(Issue 11) pp:2684-2687

Publication Date(Web):May 13, 2013

DOI:10.1021/ol400992p

The catalytic activity of the macrocyclic phenanthroline–copper(I) complex is utilized for the Sonogashira-type reaction to synthesize [2]rotaxanes. Thus, [2]rotaxanes were prepared by reactions between terminal alkynes and aryl iodides in the presence of the macrocyclic copper complex. Bulky substituents were introduced to the substrates to stabilize the rotaxane. The bond-forming reaction proceeded selectively inside the macrocyclic complex so that the rotaxanes could be synthesized.

Synthesis of monocyclic nine-membered compounds by the [4+3+2] cycloaddition-bond cleavage strategy

Co-reporter:Ryu Yamasaki, Korehito Kato, Daichi Hanitani, Yuichiro Mutoh, Shinichi Saito

Tetrahedron Letters 2013 Volume 54(Issue 27) pp:3507-3509

Publication Date(Web):3 July 2013

DOI:10.1016/j.tetlet.2013.04.094

Monocyclic nine-membered compounds were synthesized by the cleavage of the six-membered ring of the bicyclic compounds. Thus, the bicyclic compounds which consist of six- and nine-membered rings were synthesized by the Ni-catalyzed [4+3+2] cycloaddition, and the cleavage of the N–O bond, which was incorporated in the six-membered ring, proceeded in the presence of Mo(CO)6 to yield the monocyclic compound. On the other hand, the cleavage of the C–O bond proceeded efficiently in the presence of SmI2.

Ni-Catalyzed [4+3+2] Cycloaddition of Ethyl Cyclopropylideneacetate and Dienynes: Scope and Mechanistic Insights

Co-reporter:Dr. Ryu Yamasaki;Dr. Masato Ohashi;Kyotaro Maeda;Takuya Kitamura;Minami Nakagawa;Korehito Kato;Tetsushi Fujita;Ryohei Kamura;Kazuto Kinoshita;Dr. Hyuma Masu;Dr. Isao Azumaya;Dr. Sensuke Ogoshi;Dr. Shinichi Saito

Chemistry - A European Journal 2013 Volume 19( Issue 10) pp:3415-3425

Publication Date(Web):

DOI:10.1002/chem.201204087

Abstract

A detailed study of the Ni-catalyzed [4+3+2] cycloaddition reaction between ethyl cyclopropylideneacetate and dienynes has been conducted, resulting in the development of a new method for the synthesis of compounds containing nine-membered rings. We studied the reactivity of various dienynes, together with their substituent and conformational effects. The mechanism of the reaction was probed by examining the stoichiometric reactions of the Ni complexes and dienynes.

Synthesis of Large [2]Rotaxanes. The Relationship between the Size of the Blocking Group and the Stability of the Rotaxane

Co-reporter:Shinichi Saito, Eiko Takahashi, Kouta Wakatsuki, Kazuhiko Inoue, Tomoko Orikasa, Kenta Sakai, Ryu Yamasaki, Yuichiro Mutoh, and Takeshi Kasama

The Journal of Organic Chemistry 2013 Volume 78(Issue 8) pp:3553-3560

Publication Date(Web):April 1, 2013

DOI:10.1021/jo302800t

[2]Rotaxanes with large macrocyclic phenanthrolines were prepared by the template method, and the stability of the rotaxanes was examined. Compared to the tris(biphenyl)methyl group, the tris(4-cyclohexylbiphenyl)methyl group was a larger blocking group, and the rate of the dissociation of the components decreased significantly when the thermal stability of a rotaxane with a 41-memebered ring was examined. We also succeeded in the synthesis of larger rotaxanes by the oxidative dimerization of alkynes with these bulky blocking groups, utilizing the catalytic activity of the macrocyclic phenanthroline–Cu complex.

Cycloaddition Reaction of 2-Vinylazetidines with Benzyne: A Facile Access to 1-Benzazocine Derivatives

Co-reporter:Takashi Aoki, Shunsuke Koya, Ryu Yamasaki, and Shinichi Saito

Organic Letters 2012 Volume 14(Issue 17) pp:4506-4509

Publication Date(Web):August 10, 2012

DOI:10.1021/ol3019924

The cycloaddition reaction of 2-vinylazetidines with benzyne proceeded smoothly without a catalyst, and various benzazocine derivatives were isolated in good to high yields. The scope of the reaction, as well as the reactions of other arynes, has been studied.

[5 + 2] Cycloaddition Reaction of 2-Vinylaziridines and Sulfonyl Isocyanates. Synthesis of Seven-Membered Cyclic Ureas

Co-reporter:Eri Kanno, Kenichi Yamanoi, Shunsuke Koya, Isao Azumaya, Hyuma Masu, Ryu Yamasaki, and Shinichi Saito

The Journal of Organic Chemistry 2012 Volume 77(Issue 5) pp:2142-2148

Publication Date(Web):January 31, 2012

DOI:10.1021/jo201959a

The [5 + 2] cycloaddition reaction of 2-vinylaziridines with sulfonyl isocyanates proceeded smoothly under mild conditions, and various cyclic ureas were isolated in high yields. The remarkable solvent effect on the reaction was observed, and the preferential formation of the seven-membered ring occurred when the reaction was carried out in CH2Cl2. The scope and limitation were studied, and the mechanism of this reaction was discussed. This study provides a new and simple method for the synthesis of seven-membered cyclic ureas.

Synthesis and structure of bidentate NHC-metal complexes with xanthene skeleton: the formation of cis and trans complexes

Co-reporter:Shinichi Saito, Takaya Kobayashi, Takeshi Makino, Hiromitsu Yamaguchi, Hiroki Muto, Isao Azumaya, Kosuke Katagiri, Ryu Yamasaki

Tetrahedron 2012 68(43) pp: 8931-8936

Publication Date(Web):

DOI:10.1016/j.tet.2012.08.016

Synthesis and properties of phenylogous amides

Co-reporter:Ryu Yamasaki, Hirokazu Ikeda, Hyuma Masu, Isao Azumaya, Shinichi Saito

Tetrahedron 2012 68(40) pp: 8450-8456

Publication Date(Web):

DOI:10.1016/j.tet.2012.07.084

Preparation of Shape-Persistent Macrocycles with a Single Pyridine Unit by Double Cross-Coupling Reactions of Aryl Bromides and Alkynes

Co-reporter:Ryu Yamasaki, Atsushi Shigeto, and Shinichi Saito

The Journal of Organic Chemistry 2011 Volume 76(Issue 24) pp:10299-10305

Publication Date(Web):November 11, 2011

DOI:10.1021/jo2018944

A double Sonogashira-type coupling reaction between aryl bromides and alkynes using a catalytic Pd/XPhos (2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl) system was introduced as an efficient method for the synthesis of shape-persistent macrocycles (SPMs). This approach is advantageous in the synthesis of SPMs with a single pyridine unit.

Synthesis and Structure of Dinuclear Silver(I) and Palladium(II) Complexes of 2,7-Bis(methylene)naphthalene-Bridged Bis-N-Heterocyclic Carbene Ligands

Co-reporter:Shinichi Saito, Mitsuya Saika, Ryu Yamasaki, Isao Azumaya, and Hyuma Masu

Organometallics 2011 Volume 30(Issue 6) pp:1366-1373

Publication Date(Web):February 22, 2011

DOI:10.1021/om1008583

We synthesized a series of new Ag2(bis-NHC)2 complexes from the corresponding bisimidazolium salts tethered with 2,7-dimethylnaphthalene-bridged bis-NHC ligands. The reaction proceeded in a selective manner, and the Ag2(bis-NHC)2 complexes were isolated in good to high yields. The Ag complexes were converted to the Pd2(bis-NHC)2 complexes efficiently. It is important to choose proper conditions for the conversion of the silver complexes to the palladium complexes, depending on the structure of the ligand: the effect of the counteranion was significant. The structures of the complexes were studied by X-ray crystallographic analyses and compared with the corresponding monodentate NHC complexes. The catalytic activity of the Pd complexes for the Mizoroki−Heck reaction was examined.

Ring expansion reactions of ethyl cyclopropylideneacetate and benzosilacyclobutenes: formal σ bond cross metathesis

Co-reporter:Shinichi Saito, Takahiro Yoshizawa, Shinya Ishigami, Ryu Yamasaki

Tetrahedron Letters 2010 Volume 51(Issue 46) pp:6028-6030

Publication Date(Web):17 November 2010

DOI:10.1016/j.tetlet.2010.09.031

The ring expansion reaction of ethyl cyclopropylideneacetate (1) with benzosilacyclobutenes proceeded smoothly in the presence of Ni(cod)2-TOPP (tribiphenyl-2-yl phosphite) to give benzosilacycloheptenes in good yields. This formal σ bond metathesis reaction proceeded in a selective manner. The Ni-catalyzed reaction of 1 with biphenylenes was also examined.

Synthesis of Nine-Membered Carbocycles by the [4+3+2]Cycloaddition Reaction of Ethyl Cyclopropylideneacetate and Dienynes

Co-reporter:Shinichi Saito Dr.;Kyotaro Maeda;Ryu Yamasaki Dr.;Takuya Kitamura;Minami Nakagawa;Korehito Kato;Isao Azumaya Dr.;Hyuma Masu Dr.

Angewandte Chemie International Edition 2010 Volume 49( Issue 10) pp:1830-1833

Publication Date(Web):

DOI:10.1002/anie.200907052

Synthesis and Characterization of Silver and Palladium Complexes with Xanthene-Based N-Heterocyclic Carbene−Oxazoline Ligands

Co-reporter:Takeshi Makino, Ryu Yamasaki, Isao Azumaya, Hyuma Masu, and Shinichi Saito

Organometallics 2010 Volume 29(Issue 23) pp:6291-6297

Publication Date(Web):November 16, 2010

DOI:10.1021/om100673e

We synthesized xanthenes substituted with two different donor ligand units, N-heterocyclic carbene (NHC) and oxazoline, by the sequential coupling reaction. Silver complexes 15 and 19 were prepared by the reaction between the xanthene derivatives and Ag2O. Pd complexes 16 and 20 were also synthesized by the reaction of the corresponding silver complexes with Pd(PhCN)2Cl2. X-ray crystallographic analysis revealed that complexes 15-PF6, 16, and 20 adopted trans configurations, while the Ag atom of 15-Cl coordinated only to the NHC ligand.

Synthesis of Nine-Membered Carbocycles by the [4+3+2]Cycloaddition Reaction of Ethyl Cyclopropylideneacetate and Dienynes

Co-reporter:Shinichi Saito Dr.;Kyotaro Maeda;Ryu Yamasaki Dr.;Takuya Kitamura;Minami Nakagawa;Korehito Kato;Isao Azumaya Dr.;Hyuma Masu Dr.

Angewandte Chemie 2010 Volume 122( Issue 10) pp:1874-1877

Publication Date(Web):

DOI:10.1002/ange.200907052

Selective Synthesis of Eight-Membered Cyclic Ureas by the [6 + 2] Cycloaddition Reaction of 2-Vinylazetidines and Electron-Deficient Isocyanates

Co-reporter:Shunsuke Koya, Kenichi Yamanoi, Ryu Yamasaki, Isao Azumaya, Hyuma Masu and Shinichi Saito

Organic Letters 2009 Volume 11(Issue 23) pp:5438-5441

Publication Date(Web):November 11, 2009

DOI:10.1021/ol902299p

The [6 + 2] cycloaddition reaction of 2-vinylazetidines with electron-deficient isocyanates such as tosyl isocyanate proceeded smoothly in the absence of the catalyst at room temperature, and various cyclic ureas were isolated in good to high yields. Electron-deficient allenes also reacted with the 2-vinylazetidine, and the corresponding azocine derivatives were isolated.

Synthesis of Vinylcycloheptadienes by the Nickel-Catalyzed Three-Component [3 + 2 + 2] Cocyclization. Application to the Synthesis of Polycyclic Compounds

Co-reporter:Shinsuke Komagawa, Kouhei Takeuchi, Ikuo Sotome, Isao Azumaya, Hyuma Masu, Ryu Yamasaki and Shinichi Saito

The Journal of Organic Chemistry 2009 Volume 74(Issue 9) pp:3323-3329

Publication Date(Web):April 6, 2009

DOI:10.1021/jo900189g

The nickel-catalyzed [3 + 2 + 2] cycloaddition of ethyl cyclopropylideneacetate and conjugated enynes proceeded smoothly and divinylcycloheptadienes were isolated in high yields. The three-component cocyclization of ethyl cyclopropylideneacetate, conjugated enynes, and (trimethylsilyl)acetylene also proceeded in a highly selective manner to afford vinylcycloheptadienes, which were reacted with various dienophiles. This study provided a new, short-step synthesis of polycyclic compounds with cycloheptane skeleton.

Ni-catalyzed [3+2+2] cycloaddition of ethyl cyclopropylideneacetate and 1,3-diynes. Application to the three-component cycloaddition

Co-reporter:Ryu Yamasaki, Ikuo Sotome, Shunsuke Komagawa, Isao Azumaya, Hyuma Masu, Shinichi Saito

Tetrahedron Letters 2009 50(10) pp: 1143-1145

Publication Date(Web):

DOI:10.1016/j.tetlet.2008.12.092

Thermal and catalytic isomerization of exomethylenecycloheptadienes. Experimental and theoretical studies

Co-reporter:Yukiko Fukusaki, Jun Miyazaki, Isao Azumaya, Kosuke Katagiri, Shinsuke Komagawa, Ryu Yamasaki, Shinichi Saito

Tetrahedron 2009 65(51) pp: 10631-10636

Publication Date(Web):

DOI:10.1016/j.tet.2009.10.065

Synthesis of [2]Catenanes by Oxidative Intramolecular Diyne Coupling Mediated by Macrocyclic Copper(I) Complexes

Co-reporter:Yuta Sato;Ryu Yamasaki Dr. Dr.

Angewandte Chemie International Edition 2009 Volume 48( Issue 3) pp:504-507

Publication Date(Web):

DOI:10.1002/anie.200804864

Synthesis of [2]Catenanes by Oxidative Intramolecular Diyne Coupling Mediated by Macrocyclic Copper(I) Complexes

Co-reporter:Yuta Sato;Ryu Yamasaki Dr. Dr.

Angewandte Chemie 2009 Volume 121( Issue 15) pp:

Publication Date(Web):

DOI:10.1002/ange.200990077

No abstract is available for this article.

Synthesis of [2]Catenanes by Oxidative Intramolecular Diyne Coupling Mediated by Macrocyclic Copper(I) Complexes

Co-reporter:Yuta Sato;Ryu Yamasaki Dr. Dr.

Angewandte Chemie International Edition 2009 Volume 48( Issue 15) pp:

Publication Date(Web):

DOI:10.1002/anie.200990075

No abstract is available for this article.

Synthesis of [2]Catenanes by Oxidative Intramolecular Diyne Coupling Mediated by Macrocyclic Copper(I) Complexes

Co-reporter:Yuta Sato;Ryu Yamasaki Dr. Dr.

Angewandte Chemie 2009 Volume 121( Issue 3) pp:512-515

Publication Date(Web):

DOI:10.1002/ange.200804864

Synthesis, Structure, and Solvent-Induced Spontaneous Homochiral Assembly of Bidentate Bis(N,N-diaryl-N-heterocyclic carbene)-Palladium Complexes

Co-reporter:Takeshi Makino;Hyuma Masu;Kosuke Katagiri;Ryu Yamasaki;Isao Azumaya

European Journal of Inorganic Chemistry 2008 Volume 2008( Issue 31) pp:4861-4865

Publication Date(Web):

DOI:10.1002/ejic.200800831

Abstract

A series of new bidentate bis(N-heterocyclic carbene)-palladium complexes 4a–e and 6 with xanthene framework was synthesized. The X-ray analyses of the complexes revealed that the complexes have conformational chirality. Homochiral crystals of 4a and 6 were obtained by recrystallization from THF or 1,4-dioxane as solvent. The energy barriers for racemization of the complexes were calculated from dynamic NMR spectroscopy. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

Nickel-Catalyzed Three-Component [3+2+2] Cocyclization of Ethyl Cyclopropylideneacetate and Alkynes—Selective Synthesis of Multisubstituted Cycloheptadienes

Co-reporter:Shinsuke Komagawa Dr.

Angewandte Chemie 2006 Volume 118(Issue 15) pp:

Publication Date(Web):9 MAR 2006

DOI:10.1002/ange.200504050

Ménage à trois: Siebengliedrige Carbocyclen sind durch die Drei-Komponenten-[3+2+2]-Cycloaddition von Cyclopropylidenessigsäureethylester und zwei verschiedenen Alkinen in Gegenwart eines Ni⁰/PPh₃-Katalysators zugänglich (siehe Schema). In dieser Eintopfreaktion läuft eine hoch chemo- und regioselektive Kupplung ab, und die Cycloheptadienderivate werden isomerenrein isoliert.

Nickel-Catalyzed Three-Component [3+2+2] Cocyclization of Ethyl Cyclopropylideneacetate and AlkynesSelective Synthesis of Multisubstituted Cycloheptadienes

Co-reporter:Shinsuke Komagawa,Shinichi Saito

Angewandte Chemie International Edition 2006 45(15) pp:2446-2449

Publication Date(Web):

DOI:10.1002/anie.200504050

Ruthenium-catalyzed cycloisomerization of 1,1,2,2-tetramethyl-1,2-divinyldisilane: Selective formation of a five-membered silacycle

Co-reporter:Shinichi Saito, Kouhei Takeuchi, Takaya Mise, Yasuo Wakatsuki

Journal of Organometallic Chemistry 2005 Volume 690(Issue 14) pp:3451-3455

Publication Date(Web):15 July 2005

DOI:10.1016/j.jorganchem.2005.04.036

The cycloisomerization of 1,1,2,2-tetramethyl-1,2-divinyldisilane (1) in the presence of ruthenium–diphosphine complexes has been examined. A ruthenium–dppe (8) or a ruthenium–dppv (12) complex selectively catalyzed the reaction and 1,1,2,3,3-pentamethyl-1,3-disilycyclopent-4-ene (3) was isolated as the major product. The reaction was also carried out in the presence of a deuterated ruthenium–PiPr3 complex and the incorporation of deuterium to 1,1,4,4-tetramethyl-1,4-disilacyclohex-2-ene (2) was observed. The mechanism of this reaction has been proposed.We carried out the isomerization of 1,1,2,2-tetramethyl-1,2-divinyldisilane in the presence of various ruthenium–diphosphine complexes and observed the highly selective formation of a five-membered silacycle in the presence of a ruthenium–dppv complex. The mechanism of this reaction was also discussed.

A ruthenium tellurocarbonyl (CTe) complex with a cyclopentadienyl ligand: systematic studies of a series of chalcogenocarbonyl complexes [CpRuCl(CE)(H2IMes)] (E = O, S, Se, Te)

Co-reporter:Ayumi Suzuki, Takahiro Arai, Kota Ikenaga, Yuichiro Mutoh, Noriko Tsuchida, Shinichi Saito and Youichi Ishii

Dalton Transactions 2017 - vol. 46(Issue 1) pp:NaN48-48

Publication Date(Web):2016/11/24

DOI:10.1039/C6DT04440A

Synthesis of rotacatenanes by the combination of Cu-mediated threading reaction and the template method: the dual role of one ligand

Co-reporter:Ryuto Hayashi, Kota Wakatsuki, Ryu Yamasaki, Yuichiro Mutoh, Takeshi Kasama and Shinichi Saito

Chemical Communications 2014 - vol. 50(Issue 2) pp:NaN206-206

Publication Date(Web):2013/10/24

DOI:10.1039/C3CC47425A