Eiji Shirakawa - Cochemist

Base-promoted dehydrogenative coupling of benzene derivatives with amides or ethers

Co-reporter:Ryota Ueno and Eiji Shirakawa

Organic & Biomolecular Chemistry 2014 vol. 12(Issue 38) pp:7469-7473

Publication Date(Web):2014/08/05

DOI:10.1039/C4OB01253D

Benzene derivatives are introduced into the dehydrogenative coupling via homolytic aromatic substitution (HAS) as arenes that couple with amides/ethers. NaOt-Bu is used as a critical promoter of HAS in combination with t-BuOOt-Bu as an oxidant.

Single-Electron-Transfer-Induced Coupling of Arylzinc Reagents with Aryl and Alkenyl Halides

Co-reporter: Eiji Shirakawa;Fumiko Tamakuni;Eugene Kusano;Nanase Uchiyama;Wataru Konagaya;Ryo Watabe; Tamio Hayashi

Angewandte Chemie International Edition 2014 Volume 53( Issue 2) pp:521-525

Publication Date(Web):

DOI:10.1002/anie.201308200

Abstract

Arylzinc reagents, prepared from aryl halides/zinc powder or aryl Grignard reagents/zinc chloride, were found to undergo coupling with aryl and alkenyl halides without the aid of transition-metal catalysis to give biaryls and styrene derivatives, respectively. In this context, we have already reported the corresponding reaction using aryl Grignard reagents instead of arylzinc reagents. Compared with the Grignard cross-coupling, the present reaction features high functional-group tolerance, whereby electrophilic groups such as alkoxycarbonyl and cyano groups are compatible as substituents on both the arylzinc reagents and the aryl halides. Aryl halides receive a single electron and thereby become activated as the corresponding anion radicals, which react with arylzinc reagents, thus leading to the cross-coupling products.

Single-Electron-Transfer-Induced Coupling of Arylzinc Reagents with Aryl and Alkenyl Halides

Co-reporter: Eiji Shirakawa;Fumiko Tamakuni;Eugene Kusano;Nanase Uchiyama;Wataru Konagaya;Ryo Watabe; Tamio Hayashi

Angewandte Chemie 2014 Volume 126( Issue 2) pp:531-535

Publication Date(Web):

DOI:10.1002/ange.201308200

Abstract

Arylzinc reagents, prepared from aryl halides/zinc powder or aryl Grignard reagents/zinc chloride, were found to undergo coupling with aryl and alkenyl halides without the aid of transition-metal catalysis to give biaryls and styrene derivatives, respectively. In this context, we have already reported the corresponding reaction using aryl Grignard reagents instead of arylzinc reagents. Compared with the Grignard cross-coupling, the present reaction features high functional-group tolerance, whereby electrophilic groups such as alkoxycarbonyl and cyano groups are compatible as substituents on both the arylzinc reagents and the aryl halides. Aryl halides receive a single electron and thereby become activated as the corresponding anion radicals, which react with arylzinc reagents, thus leading to the cross-coupling products.

Single electron transfer-induced cross-coupling reaction of alkenyl halides with aryl Grignard reagents

Co-reporter:Eiji Shirakawa, Ryo Watabe, Takuya Murakami and Tamio Hayashi

Chemical Communications 2013 vol. 49(Issue 45) pp:5219-5221

Publication Date(Web):16 Apr 2013

DOI:10.1039/C3CC41923A

Alkenyl halides were found to undergo coupling with aryl Grignard reagents to give the corresponding styrene derivatives in a stereo-retained manner. The cross-coupling reaction is considered to proceed through a single electron transfer mechanism.

Single electron transfer-induced Grignard cross-coupling involving ion radicals as exclusive intermediates

Co-reporter:Nanase Uchiyama, Eiji Shirakawa and Tamio Hayashi

Chemical Communications 2013 vol. 49(Issue 4) pp:364-366

Publication Date(Web):15 Nov 2012

DOI:10.1039/C2CC37643A

The mechanism of the previously developed cross-coupling reaction of aryl Grignard reagents with aryl halides was explored in more detail. Single electron transfer from an aryl Grignard reagent to an aryl halide initiates a radical chain by giving an anion radical of the aryl halide. The following propagation cycle consists entirely of anion radical intermediates.

Indium-catalyzed annulation of 3-aryl- and 3-heteroarylindoles with propargyl ethers: synthesis and photoluminescent properties of aryl- and heteroaryl[c]carbazoles

Co-reporter:Yuta Nagase, Hiroyuki Shirai, Masayoshi Kaneko, Eiji Shirakawa and Teruhisa Tsuchimoto

Organic & Biomolecular Chemistry 2013 vol. 11(Issue 9) pp:1456-1459

Publication Date(Web):11 Jan 2013

DOI:10.1039/C3OB27407A

Treatment of 3-aryl- and 3-heteroarylindoles with propargyl ethers under indium catalysis successfully provided aryl- and heteroaryl[c]carbazoles, which were found to be more efficient emitters compared with the corresponding [a]-analogs.

Ruthenium-Catalyzed Transformation of Aryl and Alkenyl Triflates to Halides

Co-reporter:Yusuke Imazaki ; Eiji Shirakawa ; Ryota Ueno ;Tamio Hayashi

Journal of the American Chemical Society 2012 Volume 134(Issue 36) pp:14760-14763

Publication Date(Web):August 23, 2012

DOI:10.1021/ja307771d

Aryl triflates were transformed to aryl bromides/iodides simply by treating them with LiBr/NaI and [Cp*Ru(MeCN)3]OTf. The ruthenium complex also catalyzed the transformation of alkenyl sulfonates and phosphates to alkenyl halides under mild conditions. Aryl and alkenyl triflates undergo oxidative addition to a ruthenium(II) complex to form η1-arylruthenium and 1-ruthenacyclopropene intermediates, respectively, which are transformed to the corresponding halides.

Cross-Coupling of Aryl Grignard Reagents with Aryl Iodides and Bromides through SRN1 Pathway

Co-reporter: Eiji Shirakawa;Yumi Hayashi;Ken-ichi Itoh;Ryo Watabe;Nanase Uchiyama;Wataru Konagaya;Seiji Masui ; Tamio Hayashi

Angewandte Chemie International Edition 2012 Volume 51( Issue 1) pp:218-221

Publication Date(Web):

DOI:10.1002/anie.201106086

Cross-Coupling of Aryl Grignard Reagents with Aryl Iodides and Bromides through SRN1 Pathway

Co-reporter: Eiji Shirakawa;Yumi Hayashi;Ken-ichi Itoh;Ryo Watabe;Nanase Uchiyama;Wataru Konagaya;Seiji Masui ; Tamio Hayashi

Angewandte Chemie 2012 Volume 124( Issue 1) pp:222-225

Publication Date(Web):

DOI:10.1002/ange.201106086

Iron–Copper Cooperative Catalysis in the Reactions of Alkyl Grignard Reagents: Exchange Reaction with Alkenes and Carbometalation of Alkynes

Co-reporter:Eiji Shirakawa ; Daiji Ikeda ; Seiji Masui ; Masatoshi Yoshida ;Tamio Hayashi

Journal of the American Chemical Society 2011 Volume 134(Issue 1) pp:272-279

Publication Date(Web):November 30, 2011

DOI:10.1021/ja206745w

Iron–copper cooperative catalysis is shown to be effective for an alkene–Grignard exchange reaction and alkylmagnesiation of alkynes. The Grignard exchange between terminal alkenes (RCH═CH2) and cyclopentylmagnesium bromide was catalyzed by FeCl3 (2.5 mol %) and CuBr (5 mol %) in combination with PBu3 (10 mol %) to give RCH2CH2MgBr in high yields. 1-Alkyl Grignard reagents add to alkynes in the presence of a catalyst system consisting of Fe(acac)3, CuBr, PBu3, and N,N,N′,N′-tetramethylethylenediamine to give β-alkylvinyl Grignard reagents. The exchange reaction and carbometalation take place on iron, whereas copper assists with the exchange of organic groups between organoiron and organomagnesium species through transmetalation with these species. Sequential reactions consisting of the alkene–Grignard exchange and the alkylmagnesiation of alkynes were successfully conducted by adding an alkyne to a mixture of the first reaction. Isomerization of Grignard reagents from 2-alkyl to 1-alkyl catalyzed by Fe–Cu also is applicable as the first 1-alkyl Grignard formation step.

Iron-catalyzed oxidative coupling of arylboronic acids with benzene derivatives through homolytic aromatic substitution

Co-reporter:Nanase Uchiyama, Eiji Shirakawa, Ryo Nishikawa and Tamio Hayashi

Chemical Communications 2011 vol. 47(Issue 42) pp:11671-11673

Publication Date(Web):27 Sep 2011

DOI:10.1039/C1CC14694G

Fe(OTf)3–1,10-phenanthroline catalyzes oxidative coupling of arylboronic acids with benzene derivatives using t-BuOOt-Bu as an oxidant. The reaction proceeds through homolytic aromatic substitution with aryl radicals generated from arylboronic acids and t-BuO˙.

Iron-catalyzed aryl- and alkenyllithiation of alkynes and its application to benzosilole synthesis

Co-reporter:Eiji Shirakawa, Seiji Masui, Rintaro Narui, Ryo Watabe, Daiji Ikeda and Tamio Hayashi

Chemical Communications 2011 vol. 47(Issue 34) pp:9714-9716

Publication Date(Web):25 Jul 2011

DOI:10.1039/C1CC11989C

Phenyl- and vinyllithiums having an alkyl substituent at their ortho- and cis-position, respectively, readily added to alkynes in the presence of 5 mol% of Fe(acac)3. The reaction of o-(trimethylsilyl)phenyllithium with alkynes gave benzosiloles through an addition–cyclization sequence.

MizorokiHeck-Type Reaction Mediated by Potassium tert-Butoxide

Co-reporter: Eiji Shirakawa;Dr. Xuejing Zhang ; Tamio Hayashi

Angewandte Chemie 2011 Volume 123( Issue 20) pp:4767-4770

Publication Date(Web):

DOI:10.1002/ange.201008220

MizorokiHeck-Type Reaction Mediated by Potassium tert-Butoxide

Co-reporter: Eiji Shirakawa;Dr. Xuejing Zhang ; Tamio Hayashi

Angewandte Chemie International Edition 2011 Volume 50( Issue 20) pp:4671-4674

Publication Date(Web):

DOI:10.1002/anie.201008220

Ruthenium-catalyzed reaction of alkenyl triflates with zinc thiolates

Co-reporter:Yusuke Imazaki, Eiji Shirakawa, Tamio Hayashi

Tetrahedron 2011 67(52) pp: 10212-10215

Publication Date(Web):

DOI:10.1016/j.tet.2011.09.145

Iron-Catalyzed Oxidative Coupling of Alkylamides with Arenes through Oxidation of Alkylamides Followed by Friedel−Crafts Alkylation

Co-reporter:Eiji Shirakawa, Nanase Uchiyama, and Tamio Hayashi

The Journal of Organic Chemistry 2011 Volume 76(Issue 1) pp:25-34

Publication Date(Web):December 15, 2010

DOI:10.1021/jo102217m

FeCl3 in combination with t-BuOOt-Bu as an oxidant was found to be an efficient catalyst for oxidation of alkylamides to α-(tert-butoxy)alkylamides. FeCl2 and CuCl showed, respectively, almost the same and slightly lower activities compared with FeCl3 in the tert-butoxylation of N-phenylpyrrolidone (1a), whereas no tert-butoxylated product was obtained by use of Fe(OTf)3, RuCl3, or Zr(OTf)4. FeCl3 was found to be effective also as a catalyst for the Friedel−Crafts alkylation with thus obtained α-(tert-butoxy)alkylamides. The Friedel−Crafts alkylation proceeded smoothly also in the presence of a catalytic amount of Fe(OTf)3, RuCl3, or Zr(OTf)4. In contrast, FeCl2 and CuCl, which showed certain activity toward the tert-butoxylation, failed to promote the Friedel−Crafts alkylation. Among the transition metal complexes thus far examined, only FeCl3 showed high catalytic activities for both the oxidation and the Friedel−Crafts alkylation. The bifunctionality of FeCl3 was utilized for the oxidative coupling of alkylamides with arenes through a tandem reaction consisting of oxidation of alkylamides to α-(tert-butoxy)alkylamides and the following Friedel−Crafts alkylation. The FeCl3-catalyzed oxidative coupling is applicable to a wide variety of alkylamides and arenes, though a combination of FeCl3 with Fe(OTf)3 was found to be effective for the reaction of arenes with low nucleophilicity. A Fe(II)−Fe(III) catalytic cycle is concerned with the tert-butoxylation, whereas a Fe(III) complex as a Lewis acid catalyzes the Friedel−Crafts alkylation.

tert-Butoxide-Mediated Arylation of Benzene with Aryl Halides in the Presence of a Catalytic 1,10-Phenanthroline Derivative

Co-reporter:Eiji Shirakawa ; Ken-ichi Itoh ; Tomohiro Higashino ;Tamio Hayashi

Journal of the American Chemical Society 2010 Volume 132(Issue 44) pp:15537-15539

Publication Date(Web):October 20, 2010

DOI:10.1021/ja1080822

Sodium tert-butoxide mediates the coupling of aryl halides with benzene derivatives without the aid of transition metal catalysts but with a catalytic 1,10-phenanthroline derivative.

Iron-catalyzed carbolithiation of alkynes having no heteroatoms

Co-reporter:Eiji Shirakawa, Daiji Ikeda, Tsubasa Ozawa, Shogo Watanabe and Tamio Hayashi

Chemical Communications 2009 (Issue 14) pp:1885-1887

Publication Date(Web):19 Feb 2009

DOI:10.1039/B900345B

Alkyl- and aryllithium compoundswere found to add to alkynes having no heteroatoms in the presence of an iron or iron–copper catalyst to give various trisubstituted vinyllithium compounds.

Ruthenium-catalyzed transformation of alkenyl triflates to alkenyl halides

Co-reporter:Eiji Shirakawa, Yusuke Imazaki and Tamio Hayashi

Chemical Communications 2009 (Issue 34) pp:5088-5090

Publication Date(Web):26 May 2009

DOI:10.1039/B907761H

In the presence of a ruthenium catalyst, alkenyl triflates were found to be transformed to the corresponding bromides, chlorides and iodides simply by treatment with a lithium halide (1.2 equiv.).

Synthesis of Methanes Having Four Different Carbon Substituents Utilizing Indium-Catalyzed Cleavage of CarbonPyrrolyl Bonds

Co-reporter:Teruhisa Tsuchimoto;Taku Ainoya;Kazuki Aoki;Tatsuya Wagatsuma

European Journal of Organic Chemistry 2009 Volume 2009( Issue 15) pp:2437-2440

Publication Date(Web):

DOI:10.1002/ejoc.200900246

Abstract

A pyrrolyl group bound to an sp³ carbon atom in gem-dipyrrolylalkanes was found to be successfully replaced by a certain range of carbon nucleophiles in the presence of an indium catalyst. The reaction can also be performed efficiently as a three-component assembly of alkynes, pyrroles, and carbon nucleophiles in one batch. The strategy is highly useful to synthesize methanes having four different carbon substituents. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Fe–Cu cooperative catalysis in the isomerization of alkyl Grignard reagents

Co-reporter:Eiji Shirakawa, Daiji Ikeda, Shigeru Yamaguchi and Tamio Hayashi

Chemical Communications 2008 (Issue 10) pp:1214-1216

Publication Date(Web):04 Jan 2008

DOI:10.1039/B717717H

Alkyl Grignard reagents were found to be isomerized to more stable ones in high isomerization ratios (>99%) under cooperative catalysis by iron and copper, which promote isomerization of alkyl groups and transmetalation between Fe–Mg, respectively.

Palladium-catalyzed conjugate reduction of enones into α,β-dideuterioketones with hexamethyldisilane and deuterium oxide

Co-reporter:Hidehito Otsuka, Eiji Shirakawa and Tamio Hayashi

Chemical Communications 2007 (Issue 18) pp:1819-1821

Publication Date(Web):08 Feb 2007

DOI:10.1039/B618107D

Conjugated enones are reduced by readily available Me3SiSiMe3 and D2O in the presence of a catalytic amount of [PdCl(η3-C3H5)]2–PPh3 to give α,β-dideuterioketones.

Cobalt-catalyzed cross-coupling of alkynyl Grignard reagents with alkenyl triflates

Co-reporter:Eiji Shirakawa, Takahiro Sato, Yusuke Imazaki, Takahiro Kimura and Tamio Hayashi

Chemical Communications 2007 (Issue 43) pp:4513-4515

Publication Date(Web):28 Aug 2007

DOI:10.1039/B711884H

Alkenyl triflates in combination with Co(acac)3 as a catalyst were found to be excellent coupling partners of alkynyl Grignard reagents, where no special additives (even a phosphine ligand) but a common solvent, THF, are required to obtain variously substituted enynes.

Palladium-catalyzed silylation of alcohols with hexamethyldisilane

Co-reporter:Eiji Shirakawa, Koji Hironaka, Hidehito Otsuka and Tamio Hayashi

Chemical Communications 2006 (Issue 37) pp:3927-3929

Publication Date(Web):04 Aug 2006

DOI:10.1039/B608958E

The combination of hexamethyldisilane and a catalytic amount of [PdCl(η3-C3H5)]2–PPh3 was found to be effective for the trimethylsilylation of alcohols, where both of the two trimethylsilyl groups of hexamethyldisilane were transferred to alcohols without coproduction of any stoichiometric amount of byproduct but H2.

Nickel-Catalyzed Addition of Organoboronates to 1,2-Dienes and the Corresponding Three-Component Reaction with an Alkyne

Co-reporter:Go Takahashi;Teruhisa Tsuchimoto;Yusuke Kawakami

Advanced Synthesis & Catalysis 2006 Volume 348(Issue 7-8) pp:

Publication Date(Web):5 MAY 2006

DOI:10.1002/adsc.200505445

A Ni(cod)₂–aminophosphine complex catalyzed the addition of aryl- and alkenylboronates to 1,2-dienes to give the hydroarylation and hydroalkenylation products of the 1,2-dienes, whereas the hydroarylation products of a 1,2-diene and an alkyne were obtained with a Ni(cod)₂–PPh₃ catalyst.

Regio- and Stereoselective Decarbonylative Carbostannylation of Alkynes Catalyzed by Pd/C

Co-reporter:Yoshiaki Nakao Dr.;Jun Satoh Dr.;Tamejiro Hiyama Dr.

Angewandte Chemie 2006 Volume 118(Issue 14) pp:

Publication Date(Web):3 MAR 2006

DOI:10.1002/ange.200504283

Weg mit dem CO: Propargyl-2-furoate lassen sich durch decarbonylierende Carbostannylierung in Gegenwart von Pd/C hoch regio- und stereoselektiv an der Dreifachbindung aryl-, alkenyl- und alkylstannylieren. Dies liefert eine Vielzahl funktionalisierter Alkenylstannane mit nucleophilen Alkenylstannan- und elektrophilen Allylfuroat-Einheiten, die durch Kupplungsreaktionen weiter verändert werden können.

Regio- and Stereoselective Decarbonylative Carbostannylation of Alkynes Catalyzed by Pd/C

Co-reporter:Yoshiaki Nakao, Jun Satoh, Eiji Shirakawa,Tamejiro Hiyama

Angewandte Chemie International Edition 2006 45(14) pp:2271-2274

Publication Date(Web):

DOI:10.1002/anie.200504283

Reduction of alkynes into 1,2-dideuterioalkenes with hexamethyldisilane and deuterium oxide in the presence of a palladium catalyst

Co-reporter:Eiji Shirakawa, Hidehito Otsuka and Tamio Hayashi

Chemical Communications 2005 (Issue 47) pp:5885-5886

Publication Date(Web):02 Nov 2005

DOI:10.1039/B512245G

A combination of hexamethyldisilane and deuterium oxide was found to work as a deuterium transfer reagent for alkynes in the presence of a catalytic amount of a palladium complex to give (E)-1,2-dideuterioalkenes selectively through the corresponding (Z)-isomer.

Alkynes as activators in the nickel-catalysed addition of organoboronates to aldehydes

Co-reporter:Go Takahashi, Eiji Shirakawa, Teruhisa Tsuchimoto and Yusuke Kawakami

Chemical Communications 2005 (Issue 11) pp:1459-1461

Publication Date(Web):25 Jan 2005

DOI:10.1039/B417353H

Alkynes act not as substrates but as co-catalysts in the presence of a nickel catalyst, an organoboronate and an aldehyde to promote the addition reaction between the substrates in combination with H2O.

Synthesis of multisubstituted 1,3-butadienes using the ruthenium-catalysed double addition of trimethylsilyldiazomethane to alkynylboronates

Co-reporter:Ryotaro Morita, Eiji Shirakawa, Teruhisa Tsuchimoto and Yusuke Kawakami

Organic & Biomolecular Chemistry 2005 vol. 3(Issue 7) pp:1263-1268

Publication Date(Web):28 Feb 2005

DOI:10.1039/B501990G

The ruthenium-catalysed double addition of trimethylsilyldiazomethane to alkynes developed by Dixneuf and co-workers was applied to the synthesis of 2-alkyl- or 2-aryl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1,4-bis(trimethylsilyl)-1,3-butadienes by use of alkynylboronates instead of alkynes. Di- and tetrasubstituted 1,3-butadienes were prepared from a 2-boryl-1,4-disilyl-1,3-butadiene, using the Suzuki–Miyaura coupling reaction, iodolysis of the alkenylsilane moieties with N-iodosuccinimide and hydrolysis of the carbon–silicon bonds with trifluoroacetic acid. The same compound was converted also to a bicyclic compound, a trisubstituted 1,3-butadiene and a dienone through the Diels–Alder reaction, oxidation of the alkenylboronate moiety and the Mukaiyama aldol reaction.

Easy Access to Aryl- and Heteroaryl-Annulated[a]carbazoles by the Indium-Catalyzed Reaction of 2-Arylindoles with Propargyl Ethers

Co-reporter:Teruhisa Tsuchimoto Dr.;Hiromichi Matsubayashi;Masayoshi Kaneko Dr.;Yusuke Kawakami Dr.

Angewandte Chemie 2005 Volume 117(Issue 9) pp:

Publication Date(Web):21 JAN 2005

DOI:10.1002/ange.200462280

Indium und Indole: Ein Indiumsalz katalysiert die hoch regioselektive Fusion von 2-Arylindolen und Propargylethern zu anellierten Aryl- und Heteroaryl[a]carbazolen. Dabei gelangen zwei unterschiedliche C-C-Kupplungen in einem Rutsch (siehe Schema).

Easy Access to Aryl- and Heteroaryl-Annulated[a]carbazoles by the Indium-Catalyzed Reaction of 2-Arylindoles with Propargyl Ethers

Co-reporter:Teruhisa Tsuchimoto Dr.;Hiromichi Matsubayashi;Masayoshi Kaneko Dr.;Yusuke Kawakami Dr.

Angewandte Chemie International Edition 2005 Volume 44(Issue 9) pp:

Publication Date(Web):21 JAN 2005

DOI:10.1002/anie.200462280

Indoles and indium: An indium salt catalyzes the assembly of 2-arylindoles and propargyl ethers into diverse aryl- and heteroaryl-annulated[a]carbazoles in a highly regioselective manner, in which two different modes of carbon–carbon bond-forming reactions are successfully incorporated in one step (see scheme).

A p-phosphinophenolate ligand for the palladium-catalysed arylation of alkenes

Co-reporter:Eiji Shirakawa, Keijiro Ishii and Teruhisa Tsuchimoto

Chemical Communications 2004 (Issue 23) pp:2752-2753

Publication Date(Web):19 Oct 2004

DOI:10.1039/B411125G

A triphenylphosphine having a strong electron-donating group, an oxyanion, at the para position of one of the benzene rings was found to show much higher efficiency compared with other structurally related triarylphosphines in the palladium-catalysed arylation of alkenes.

Nickel-catalyzed acylstannylation and alkynylstannylation of 1,2-dienes

Co-reporter:Yoshiaki Nakao, Eiji Shirakawa, Teruhisa Tsuchimoto, Tamejiro Hiyama

Journal of Organometallic Chemistry 2004 Volume 689(Issue 23) pp:3701-3721

Publication Date(Web):15 November 2004

DOI:10.1016/j.jorganchem.2004.07.037

Carbostannylation of 1,2-dienes using acyl- and alkynylstannanes was achieved by means of nickel catalysis. In particular, acylstannylation of 1,2-dienes could be carried out with bis(1,5-cyclooctadiene)nickel [Ni(cod)2] and acylstannanes to give selectively α-acylmethyl(vinyl)stannanes. The reaction was also applicable to acylstannanes prepared in situ by protonolysis of α-alkoxyalkenylstannanes or by reactions of α-silyloxyvinylstannanes with aldehyde acetals. For alkynylstannylation, a combination of Ni(cod)2 and 1,3-bis(diphenylphosphino)propane (dppp) was found to be effective to afford α-alkynylmethyl(vinyl)stannanes, whereas the Ni(cod)2–1,3-bis(dimethylphosphino)propane (dmpp) catalyst switched the regioselectivity to give (Z)-α-alkynylmethyl(alkenyl)stannanes. The acylstannylation products were successfully converted into various conjugated or unconjugated enones by a combination of cross-coupling and NaH-catalyzed isomerization. The alkynylstannylation products were transformed by cross- or homo-coupling reactions to various enynes or 2,3-bis(alkynylmethyl)-1,3-dienes, versatile precursors for variously substituted polycyclic compounds.Acylstannanes and alkynylstannanes were found to add across 1,2-dienes to give various alkenylstannanes in the presence of a nickel(0) catalyst. The regiochemistry of the reaction is switchable by proper choice of a ligand. Resulting carbostannylation products were found to be versatile precursors for various conjugated compounds and polycyclic frameworks.

Nickel-Catalyzed Tandem Carbostannylation of Alkynes and 1,2-Dienes with Alkynylstannanes

Co-reporter:Eiji Shirakawa Dr.;Youko Yamamoto;Yoshiaki Nakao;Shinichi Oda;Teruhisa Tsuchimoto Dr.;Tamejiro Hiyama Dr.

Angewandte Chemie 2004 Volume 116(Issue 26) pp:

Publication Date(Web):22 JUN 2004

DOI:10.1002/ange.200353649

Alkine und 1,2-Diene inserieren in die Kohlenstoff-Zinn-Bindung von Alkinylstannanen. Bei dieser nickelkatalysierten Reaktion entsteht eine Vielfalt an Stannyldieninen (siehe Schema). Hierbei handelt es sich um das erste Beispiel einer übergangsmetallkatalysierten Tandem-Carbometallierung von zwei verschiedenen ungesättigten Kohlenstoff-Kohlenstoff-Bindungen.

Zirconium Triflate Catalyzed Direct Coupling Reaction of Lactams with Heterocyclic Arenes under Atmospheric Oxygen

Co-reporter:Teruhisa Tsuchimoto Dr.;Yoshitaka Ozawa;Ryoju Negoro Dr.;Yusuke Kawakami Dr.

Angewandte Chemie 2004 Volume 116(Issue 32) pp:

Publication Date(Web):9 AUG 2004

DOI:10.1002/ange.200460429

Gezielt gekuppelt: In einer dehydrierenden Kupplung von sp²- und sp³-Kohlenstoffzentren wurden hohe Umsatzzahlen erzielt. Ein Zirconiumkatalysator vermittelt diese Kupplungen von Heteroarenen mit Lactamen in einer Sauerstoffatmosphäre. Dabei reagiert das Lactam ausschließlich an dem Kohlenstoffatom, das dem Stickstoffatom benachbart ist (siehe Schema).

Zirconium Triflate Catalyzed Direct Coupling Reaction of Lactams with Heterocyclic Arenes under Atmospheric Oxygen

Co-reporter:Teruhisa Tsuchimoto Dr.;Yoshitaka Ozawa;Ryoju Negoro Dr.;Yusuke Kawakami Dr.

Angewandte Chemie International Edition 2004 Volume 43(Issue 32) pp:

Publication Date(Web):9 AUG 2004

DOI:10.1002/anie.200460429

Exclusive coupling: High turnover numbers were attained in the dehydrogenative coupling reaction between C(sp²) and C(sp³) atoms. A zirconium catalyst mediates the coupling reactions of heterocyclic arenes and lactams exclusively at the carbon atom adjacent to the nitrogen atom of the latter under an oxygen atmosphere (see scheme).

Nickel-Catalyzed Tandem Carbostannylation of Alkynes and 1,2-Dienes with Alkynylstannanes

Co-reporter:Eiji Shirakawa Dr.;Youko Yamamoto;Yoshiaki Nakao;Shinichi Oda;Teruhisa Tsuchimoto Dr.;Tamejiro Hiyama Dr.

Angewandte Chemie International Edition 2004 Volume 43(Issue 26) pp:

Publication Date(Web):22 JUN 2004

DOI:10.1002/anie.200353649

Alkynes and 1,2-dienes insert into the carbon–tin bond of alkynylstannanes to afford various stannyldienynes in the presence of a nickel catalyst (see scheme). This is the first example of a transition-metal-catalyzed tandem carbometalation of two different carbon–carbon unsaturated bonds.

Palladium-catalyzed conjugate reduction of enones into α,β-dideuterioketones with hexamethyldisilane and deuterium oxide

Co-reporter:Hidehito Otsuka, Eiji Shirakawa and Tamio Hayashi

Chemical Communications 2007(Issue 18) pp:NaN1821-1821

Publication Date(Web):2007/02/08

DOI:10.1039/B618107D

Conjugated enones are reduced by readily available Me3SiSiMe3 and D2O in the presence of a catalytic amount of [PdCl(η3-C3H5)]2–PPh3 to give α,β-dideuterioketones.

Single electron transfer-induced cross-coupling reaction of alkenyl halides with aryl Grignard reagents

Co-reporter:Eiji Shirakawa, Ryo Watabe, Takuya Murakami and Tamio Hayashi

Chemical Communications 2013 - vol. 49(Issue 45) pp:NaN5221-5221

Publication Date(Web):2013/04/16

DOI:10.1039/C3CC41923A

Alkenyl halides were found to undergo coupling with aryl Grignard reagents to give the corresponding styrene derivatives in a stereo-retained manner. The cross-coupling reaction is considered to proceed through a single electron transfer mechanism.

Iron-catalyzed aryl- and alkenyllithiation of alkynes and its application to benzosilole synthesis

Co-reporter:Eiji Shirakawa, Seiji Masui, Rintaro Narui, Ryo Watabe, Daiji Ikeda and Tamio Hayashi

Chemical Communications 2011 - vol. 47(Issue 34) pp:NaN9716-9716

Publication Date(Web):2011/07/25

DOI:10.1039/C1CC11989C

Phenyl- and vinyllithiums having an alkyl substituent at their ortho- and cis-position, respectively, readily added to alkynes in the presence of 5 mol% of Fe(acac)3. The reaction of o-(trimethylsilyl)phenyllithium with alkynes gave benzosiloles through an addition–cyclization sequence.

Iron-catalyzed oxidative coupling of arylboronic acids with benzene derivatives through homolytic aromatic substitution

Co-reporter:Nanase Uchiyama, Eiji Shirakawa, Ryo Nishikawa and Tamio Hayashi

Chemical Communications 2011 - vol. 47(Issue 42) pp:NaN11673-11673

Publication Date(Web):2011/09/27

DOI:10.1039/C1CC14694G

Fe(OTf)3–1,10-phenanthroline catalyzes oxidative coupling of arylboronic acids with benzene derivatives using t-BuOOt-Bu as an oxidant. The reaction proceeds through homolytic aromatic substitution with aryl radicals generated from arylboronic acids and t-BuO˙.

Cobalt-catalyzed cross-coupling of alkynyl Grignard reagents with alkenyl triflates

Co-reporter:Eiji Shirakawa, Takahiro Sato, Yusuke Imazaki, Takahiro Kimura and Tamio Hayashi

Chemical Communications 2007(Issue 43) pp:NaN4515-4515

Publication Date(Web):2007/08/28

DOI:10.1039/B711884H

Alkenyl triflates in combination with Co(acac)3 as a catalyst were found to be excellent coupling partners of alkynyl Grignard reagents, where no special additives (even a phosphine ligand) but a common solvent, THF, are required to obtain variously substituted enynes.

Fe–Cu cooperative catalysis in the isomerization of alkyl Grignard reagents

Co-reporter:Eiji Shirakawa, Daiji Ikeda, Shigeru Yamaguchi and Tamio Hayashi

Chemical Communications 2008(Issue 10) pp:NaN1216-1216

Publication Date(Web):2008/01/04

DOI:10.1039/B717717H

Alkyl Grignard reagents were found to be isomerized to more stable ones in high isomerization ratios (>99%) under cooperative catalysis by iron and copper, which promote isomerization of alkyl groups and transmetalation between Fe–Mg, respectively.

Single electron transfer-induced Grignard cross-coupling involving ion radicals as exclusive intermediates

Co-reporter:Nanase Uchiyama, Eiji Shirakawa and Tamio Hayashi

Chemical Communications 2013 - vol. 49(Issue 4) pp:NaN366-366

Publication Date(Web):2012/11/15

DOI:10.1039/C2CC37643A

The mechanism of the previously developed cross-coupling reaction of aryl Grignard reagents with aryl halides was explored in more detail. Single electron transfer from an aryl Grignard reagent to an aryl halide initiates a radical chain by giving an anion radical of the aryl halide. The following propagation cycle consists entirely of anion radical intermediates.

Indium-catalyzed annulation of 3-aryl- and 3-heteroarylindoles with propargyl ethers: synthesis and photoluminescent properties of aryl- and heteroaryl[c]carbazoles

Co-reporter:Yuta Nagase, Hiroyuki Shirai, Masayoshi Kaneko, Eiji Shirakawa and Teruhisa Tsuchimoto

Organic & Biomolecular Chemistry 2013 - vol. 11(Issue 9) pp:NaN1459-1459

Publication Date(Web):2013/01/11

DOI:10.1039/C3OB27407A

Treatment of 3-aryl- and 3-heteroarylindoles with propargyl ethers under indium catalysis successfully provided aryl- and heteroaryl[c]carbazoles, which were found to be more efficient emitters compared with the corresponding [a]-analogs.

Base-promoted dehydrogenative coupling of benzene derivatives with amides or ethers

Co-reporter:Ryota Ueno and Eiji Shirakawa

Organic & Biomolecular Chemistry 2014 - vol. 12(Issue 38) pp:NaN7473-7473

Publication Date(Web):2014/08/05

DOI:10.1039/C4OB01253D

Benzene derivatives are introduced into the dehydrogenative coupling via homolytic aromatic substitution (HAS) as arenes that couple with amides/ethers. NaOt-Bu is used as a critical promoter of HAS in combination with t-BuOOt-Bu as an oxidant.

Iron-catalyzed carbolithiation of alkynes having no heteroatoms

Co-reporter:Eiji Shirakawa, Daiji Ikeda, Tsubasa Ozawa, Shogo Watanabe and Tamio Hayashi

Chemical Communications 2009(Issue 14) pp:NaN1887-1887

Publication Date(Web):2009/02/19

DOI:10.1039/B900345B

Alkyl- and aryllithium compoundswere found to add to alkynes having no heteroatoms in the presence of an iron or iron–copper catalyst to give various trisubstituted vinyllithium compounds.

Ruthenium-catalyzed transformation of alkenyl triflates to alkenyl halides

Co-reporter:Eiji Shirakawa, Yusuke Imazaki and Tamio Hayashi

Chemical Communications 2009(Issue 34) pp:

Publication Date(Web):

DOI:10.1039/B907761H