Kei Manabe

Name:

Organization: University of Shizuoka

Department: School of Pharmaceutical Sciences

Title:

Chemicals
References

Three-step synthesis of 2,5,7-trisubstituted indoles from N-acetyl-2,4,6-trichloroaniline using Pd-catalyzed site-selective cross-coupling

Co-reporter:Miyuki Yamaguchi

Organic & Biomolecular Chemistry 2017 vol. 15(Issue 31) pp:6645-6655

Publication Date(Web):2017/08/09

DOI:10.1039/C7OB01547J

We report a facile three-step synthesis of 2,5,7-trisubstituted indoles from N-acetyl-2,4,6-trichloroaniline, with the first step featuring Pd/dihydroxyterphenylphosphine (DHTP)-catalyzed ortho-selective Sonogashira coupling followed by cyclization to afford 2-substituted 5,7-dichloroindoles. Subsequent introduction of aryl or alkenyl groups at the C7 position was achieved by Pd/DHTP-catalyzed site-selective Kumada–Tamao–Corriu coupling, with further substitution of the chlorine at the C5 position (Suzuki–Miyaura coupling or Buchwald–Hartwig amination) affording 2,5,7-trisubstituted indoles.

One-Pot Synthesis of Substituted Benzo[b]furans and Indoles from Dichlorophenols/Dichloroanilines Using a Palladium–Dihydroxyterphenylphosphine Catalyst

Co-reporter:Miyuki Yamaguchi, Tomoyo Akiyama, Hirohisa Sasou, Haruka Katsumata, and Kei Manabe

The Journal of Organic Chemistry 2016 Volume 81(Issue 13) pp:5450-5463

Publication Date(Web):June 6, 2016

DOI:10.1021/acs.joc.6b00824

Disubstituted benzo[b]furans were synthesized by ortho-selective Sonogashira coupling of dichlorophenols and terminal alkynes, followed by cyclization and Suzuki–Miyaura coupling in one pot, using a palladium–dihydroxyterphenylphosphine (Cy-DHTP) catalyst. The use of substoichiometric amounts of tetrabutylammonium chloride was effective in accelerating the Suzuki–Miyaura coupling. This protocol was also successfully applied to the one-pot synthesis of disubstituted indoles from dichloroaniline derivatives.

Three-Step Synthesis of Fluoranthenes through Pd-Catalyzed Inter- and Intramolecular C–H Arylation

Co-reporter:Miyuki Yamaguchi, Mayu Higuchi, Kanae Tazawa, and Kei Manabe

The Journal of Organic Chemistry 2016 Volume 81(Issue 9) pp:3967-3974

Publication Date(Web):April 5, 2016

DOI:10.1021/acs.joc.6b00553

A three-step synthetic method for the preparation of fluoranthenes, involving Miura’s intermolecular C–H arylation, nonaflation, and intramolecular C–H arylation, has been developed. Various 1-naphthols and haloarenes were successfully used as substrates. Reaction conditions that afford high site selectivity have been developed for the intramolecular C–H arylation step.

Concise synthesis of cyclic carbonyl compounds from haloarenes using phenyl formate as the carbonyl source

Co-reporter:Hideyuki Konishi, Hiroki Nagase and Kei Manabe

Chemical Communications 2015 vol. 51(Issue 10) pp:1854-1857

Publication Date(Web):08 Dec 2014

DOI:10.1039/C4CC09413A

Various cyclic carbonyl compounds were concisely synthesized by carbonylative cyclization of haloarenes bearing nucleophilic moieties under Pd catalysis. A broad substrate scope and a feasible large-scale synthesis clearly demonstrate the high applicability of the reaction as a general, user-friendly method for access to cyclic carbonyl compounds.

Imidazole Derivatives as Accelerators for Ruthenium-Catalyzed Hydroesterification and Hydrocarbamoylation of Alkenes: Extensive Ligand Screening and Mechanistic Study

Co-reporter:Dr. Hideyuki Konishi;Takashi Muto;Dr. Tsuyoshi Ueda;Yayoi Yamada;Dr. Miyuki Yamaguchi;Dr. Kei Manabe

ChemCatChem 2015 Volume 7( Issue 5) pp:836-845

Publication Date(Web):

DOI:10.1002/cctc.201402986

Abstract

Imidazole derivatives are effective ligands for promoting the [Ru₃(CO)₁₂]-catalyzed hydroesterification of alkenes using formates. Extensive ligand screening was performed to identify 2-hydroxymethylated imidazole as the optimal ligand. Neither carbon monoxide gas nor a directing group was required, and the reaction also showed a wide substrate generality. The Ru–imidazole catalyst system also promoted intramolecular hydrocarbamoylation to afford lactams. A Ru–imidazole complex was unambiguously analyzed by X-ray crystallography, and it had a trinuclear structure derived from one [Ru₃(CO)₁₂] and two ligands. This complex was also successfully used for hydroesterification. The mechanism was examined in detail by using D- and ¹³C-labeled formates, indicating that the hydroesterification reaction proceeds by a decarbonylation–recarbonylation pathway.

Scalable synthesis of dihydroxyterphenylphosphine ligands

Co-reporter:Miyuki Yamaguchi, Kohei Suzuki, Kei Manabe

Tetrahedron 2015 Volume 71(Issue 18) pp:2743-2747

Publication Date(Web):6 May 2015

DOI:10.1016/j.tet.2015.03.030

We have developed an improved method for the synthesis of dihydroxyterphenylphosphines (DHTPs), which are important ligands used in the palladium-catalyzed ortho-selective cross-coupling of dihalophenols or dihaloanilines. This method is simple, easily scalable, and has been used to produce multigram quantities of Cy-DHTP·HBF4 and Ph-DHTP in five steps.

One-Pot Synthesis of 2,4-Disubstituted Indoles from N-Tosyl-2,3-dichloroaniline Using Palladium–Dihydroxyterphenylphosphine Catalyst

Co-reporter:Miyuki Yamaguchi and Kei Manabe

Organic Letters 2014 Volume 16(Issue 9) pp:2386-2389

Publication Date(Web):April 17, 2014

DOI:10.1021/ol500711z

4-Chloroindoles were synthesized from readily available 2,3-dichloroaniline derivatives and terminal alkynes. The catalyst composed of palladium and dicyclohexyl(dihydroxyterphenyl)phosphine (Cy-DHTP) enabled ortho-selective Sonogashira coupling, and subsequent cyclization afforded 4-chloroindoles in high yields. This transformation was successfully applied to the one-pot synthesis of 2,4-disubstituted indoles via Suzuki–Miyaura coupling after indole formation.

Repetitive Synthetic Method for o,o,p-Oligophenylenes Using C–H Arylation

Co-reporter:Kei Manabe and Takeshi Kimura

Organic Letters 2013 Volume 15(Issue 2) pp:374-377

Publication Date(Web):January 4, 2013

DOI:10.1021/ol303327k

A synthetic method for the preparation of o,o,p-oligophenylenes has been developed. It involves Miura’s C–H arylation of 2-biphenols with aryl nonaflates as the key step. Oligophenylenes with defined lengths are successfully synthesized using this method.

Palladium-Catalyzed Fluorocarbonylation Using N-Formylsaccharin as CO Source: General Access to Carboxylic Acid Derivatives

Co-reporter:Tsuyoshi Ueda, Hideyuki Konishi, and Kei Manabe

Organic Letters 2013 Volume 15(Issue 20) pp:5370-5373

Publication Date(Web):October 2, 2013

DOI:10.1021/ol4026815

N-Formylsaccharin, an easily accessible crystalline compound, has been employed as an efficient CO source in Pd-catalyzed fluorocarbonylation of aryl halides to afford the corresponding acyl fluorides in high yields. The reactions use a near-stoichiometric amount of the CO source (1.2 equiv) and tolerate diverse functional groups. The acyl fluorides obtained could be readily transformed into various carboxylic acid derivatives such as carboxylic acid, esters, thioesters, and amides in a one-pot procedure.

One-Pot Synthesis of Substituted Benzo[b]furans from Mono- and Dichlorophenols Using Palladium Catalysts Bearing Dihydroxyterphenylphosphine

Co-reporter:Miyuki Yamaguchi, Haruka Katsumata, and Kei Manabe

The Journal of Organic Chemistry 2013 Volume 78(Issue 18) pp:9270-9281

Publication Date(Web):August 16, 2013

DOI:10.1021/jo401503t

A dihydroxyterphenylphosphine bearing cyclohexyl groups on the phosphorus atom (Cy-DHTP) was found to be a powerful ligand for the palladium-catalyzed one-pot synthesis of substituted benzo[b]furans from 2-chlorophenols and terminal alkynes. This catalyst system was also applicable to the sequential one-pot synthesis of disubstituted benzo[b]furans from dichlorophenols via the Suzuki–Miyaura cross-coupling of chlorobenzo[b]furan with boronic acids. The use of two ligands, Cy-DHTP and XPhos, is the key to promoting the reactions. Mechanistic studies suggest that the Pd–Cy-DHTP catalyst is the active species in the Sonogashira cross-coupling step, while the Pd–XPhos catalyst accelerates the Suzuki–Miyaura cross-coupling step.

Palladium-Catalyzed Reductive Carbonylation of Aryl Halides with N-Formylsaccharin as a CO Source

Co-reporter:Dr. Tsuyoshi Ueda;Dr. Hideyuki Konishi;Dr. Kei Manabe

Angewandte Chemie 2013 Volume 125( Issue 33) pp:8773-8777

Publication Date(Web):

DOI:10.1002/ange.201303926

Palladium-Catalyzed Reductive Carbonylation of Aryl Halides with N-Formylsaccharin as a CO Source

Co-reporter:Dr. Tsuyoshi Ueda;Dr. Hideyuki Konishi;Dr. Kei Manabe

Angewandte Chemie International Edition 2013 Volume 52( Issue 33) pp:8611-8615

Publication Date(Web):

DOI:10.1002/anie.201303926

Palladium-Catalyzed Carbonylation of Aryl, Alkenyl, and Allyl Halides with Phenyl Formate

Co-reporter:Tsuyoshi Ueda, Hideyuki Konishi, and Kei Manabe

Organic Letters 2012 Volume 14(Issue 12) pp:3100-3103

Publication Date(Web):2017-2-22

DOI:10.1021/ol301192s

Highly efficient palladium-catalyzed carbonylation of aryl, alkenyl, and allyl halides with phenyl formate is reported. This procedure does not use carbon monoxide and affords one-carbon-elongated carboxylic acid phenyl esters in excellent yields. The reaction proceeds smoothly under mild conditions and tolerates a wide range of functional groups including aldehyde, ether, ketone, ester, and cyano groups. Furthermore, a variety of heteroaromatic bromides can be converted to the corresponding phenyl esters in high yields.

Trichlorophenyl Formate: Highly Reactive and Easily Accessible Crystalline CO Surrogate for Palladium-Catalyzed Carbonylation of Aryl/Alkenyl Halides and Triflates

Co-reporter:Tsuyoshi Ueda, Hideyuki Konishi, and Kei Manabe

Organic Letters 2012 Volume 14(Issue 20) pp:5370-5373

Publication Date(Web):September 28, 2012

DOI:10.1021/ol302593z

The high utility of 2,4,6-trichlorophenyl formate, a highly reactive and easily accessible crystalline CO surrogate, is demonstrated. The decarbonylation with NEt3 to generate CO proceeded rapidly at rt, thereby allowing external-CO-free Pd-catalyzed carbonylation of aryl/alkenyl halides and triflates. The high reactivity of the CO surrogate enabled carbonylation at rt and significantly reduced the quantities of formate to near-stoichiometric levels. The obtained trichlorophenyl esters can be readily converted to a variety of carboxylic acid derivatives in high yields.

Remarkable Improvement Achieved by Imidazole Derivatives in Ruthenium-Catalyzed Hydroesterification of Alkenes Using Formates

Co-reporter:Hideyuki Konishi, Tsuyoshi Ueda, Takashi Muto, and Kei Manabe

Organic Letters 2012 Volume 14(Issue 18) pp:4722-4725

Publication Date(Web):August 30, 2012

DOI:10.1021/ol301850y

Imidazole derivatives are revealed to be effective ligands in the Ru-catalyzed hydroesterification of alkenes using formates, affording one-carbon-elongated esters in high yields. Further, intramolecular hydroesterification was successfully performed to give lactones for the first time. Imidazole derivatives can contribute to promote the reaction as well as to suppress the undesired decarbonylation of formate. Toxic CO gas, a directing group, and large excess alkenes are not required.

Preparation of α,β-unsaturated esters and amides via external-CO-free palladium-catalyzed carbonylation of alkenyl tosylates

Co-reporter:Tsuyoshi Ueda, Hideyuki Konishi, Kei Manabe

Tetrahedron Letters 2012 Volume 53(Issue 38) pp:5171-5175

Publication Date(Web):19 September 2012

DOI:10.1016/j.tetlet.2012.07.057

Palladium-catalyzed carbonylation of tosylates with phenyl formate is described. This procedure needs neither external carbon monoxide nor any pressure-resistant apparatus. A variety of cyclic and acyclic alkenyl tosylates can be converted into the corresponding phenyl esters in good yields. Furthermore, this method is effective for the one-pot synthesis of α,β-unsaturated amides.

A Repetitive One-Step Method for Oligoarene Synthesis Using Catalyst-Controlled Chemoselective Cross-Coupling

Co-reporter:Kei Manabe, Mai Ohba, and Yuji Matsushima

Organic Letters 2011 Volume 13(Issue 9) pp:2436-2439

Publication Date(Web):April 7, 2011

DOI:10.1021/ol200676k

A method for oligoarene synthesis involving chemoselective cross-coupling as the key reaction was developed. Boronic acids with a chloro or trifluoromethanesulfonyloxy group were used as the monomer precursors with either of two chemoselective catalytic systems: Pd with P(t-Bu)3, and Pd with 1,1′-bis(diphenylphosphino)ferrocene (DPPF). This method enabled elongation by one benzene unit in every step and thus reduced the number of steps required for elongation of oligoarene chains with well-defined lengths and sequences of substituted benzene rings.

Hydroxylated terphenylphosphine ligands for palladium-catalyzed ortho-selective cross-coupling of dibromophenols, dibromoanilines, and their congeners with Grignard reagents

Co-reporter:Shunpei Ishikawa, Kei Manabe

Tetrahedron 2011 67(52) pp: 10156-10163

Publication Date(Web):

DOI:10.1016/j.tet.2011.09.013

Synthesis of hydroxylated oligoarene-type phosphines by a repetitive two-step method

Co-reporter:Shunpei Ishikawa, Kei Manabe

Tetrahedron 2010 66(1) pp: 297-303

Publication Date(Web):

DOI:10.1016/j.tet.2009.10.101

DHTP Ligands for the Highly Ortho-Selective, Palladium-Catalyzed Cross-Coupling of Dihaloarenes with Grignard Reagents: A Conformational Approach for Catalyst Improvement

Co-reporter:Shunpei Ishikawa Dr. Dr.