Co-reporter:Tomoaki Yamaguchi, Eiji Yamaguchi, and Akichika Itoh
Organic Letters March 17, 2017 Volume 19(Issue 6) pp:
Publication Date(Web):March 8, 2017
DOI:10.1021/acs.orglett.7b00026
A novel cross-dehydrogenative C(sp2)–H amination catalyzed by an organic photocatalyst is reported. The reaction is mediated by 2-tert-butylanthraquinone as a photocatalyst, harmless visible light, and aerobic oxygen as the sole oxidant without a transition-metal catalyst and or external oxidant.
Co-reporter:Yusuke Sudo, Eiji Yamaguchi, and Akichika Itoh
Organic Letters April 7, 2017 Volume 19(Issue 7) pp:
Publication Date(Web):March 21, 2017
DOI:10.1021/acs.orglett.7b00428
A metal-free photo-oxidative intermolecular C–H/C–H coupling reaction of thiophenes is demonstrated with carbonyls using a catalytic amount of molecular iodine. In this system, molecular oxygen in the air acted as a terminal oxidant to regenerate molecular iodine. A mechanistic study was also performed.
Co-reporter:Kaoru Usami, Yoshitomo Nagasawa, Eiji Yamaguchi, Norihiro Tada, and Akichika Itoh
Organic Letters 2016 Volume 18(Issue 1) pp:8-11
Publication Date(Web):December 14, 2015
DOI:10.1021/acs.orglett.5b02957
The intermolecular cyclopropanation of aromatic olefins with activated methylene compounds using iodine and visible light irradiation was described. This reaction proceeds under rare-metal-free conditions. Styrenes with various substituted groups (alkyl and electron-withdrawing groups) provided corresponding cyclopropanes in moderate to good yields.
Co-reporter:T. Yamaguchi, K. Sakairi, E. Yamaguchi, N. Tada and A. Itoh
RSC Advances 2016 vol. 6(Issue 62) pp:56892-56895
Publication Date(Web):07 Jun 2016
DOI:10.1039/C6RA04073J
A novel and efficient approach for the synthesis of quinazolines by aerobic photooxidation with an iodine reagent at room temperature is reported. This method uses harmless visible light from compact fluorescent lamps and molecular oxygen as the sole oxidant without the need for a transition-metal catalyst or harsh reaction conditions.
Co-reporter:Miyabi Taguchi, Yoshitomo Nagasawa, Eiji Yamaguchi, Norihiro Tada, Tsuyoshi Miura, Akichika Itoh
Tetrahedron Letters 2016 Volume 57(Issue 2) pp:230-232
Publication Date(Web):13 January 2016
DOI:10.1016/j.tetlet.2015.12.027
We developed an aerobic photooxidative synthesis of peroxybenzoic acids from toluenes using anthraquinone-2-carboxylic acid (AQN-2-CO2H) as a photocatalyst. We also found a one-pot epoxidation reaction of alkenes using 4-tert-butylperoxybenzoic acid produced in situ by aerobic photooxidative synthesis.
Co-reporter:Akitoshi Fujiya, Masanori Tanaka, Eiji Yamaguchi, Norihiro Tada, and Akichika Itoh
The Journal of Organic Chemistry 2016 Volume 81(Issue 16) pp:7262-7270
Publication Date(Web):May 17, 2016
DOI:10.1021/acs.joc.6b00439
We report an efficient method for the synthesis of pyrrolo[2,1-a]isoquinoline derivatives using sequential [3 + 2] cycloaddition/oxidative aromatization reactions catalyzed by methylene blue with fluorescent light irradiation under an oxygen atmosphere. The products were obtained in moderate to good yields.
Co-reporter:Tomoaki Yamaguchi;Eiji Yamaguchi;Norihiro Tada
Advanced Synthesis & Catalysis 2015 Volume 357( Issue 9) pp:2017-2021
Publication Date(Web):
DOI:10.1002/adsc.201500061
Co-reporter:Y. Nagasawa, Y. Matsusaki, T. Nobuta, N. Tada, T. Miura and A. Itoh
RSC Advances 2015 vol. 5(Issue 78) pp:63952-63954
Publication Date(Web):21 Jul 2015
DOI:10.1039/C5RA07275A
This study reports a safe, mild, and environmentally benign synthetic method toward 2-aryl-4-quinazolinones from aromatic aldehydes and aminobenzamides through a cyclization–oxidation sequence using a catalytic amount of iodine, which serves as both a Lewis acid and an oxidant, harmless visible light irradiation, and molecular oxygen as the terminal oxidant.
Co-reporter:Yuma Tachikawa, Yoshitomo Nagasawa, Sohei Furuhashi, Lei Cui, Eiji Yamaguchi, Norihiro Tada, Tsuyoshi Miura and Akichika Itoh
RSC Advances 2015 vol. 5(Issue 13) pp:9591-9593
Publication Date(Web):05 Jan 2015
DOI:10.1039/C4RA14970J
We have developed a metal-free synthetic method for 3-nitroimidazo[1,2-a]pyridines from nitroalkenes and 2-aminopyridines using catalytic amounts of iodine and aqueous hydrogen peroxide as a terminal oxidant.
Co-reporter:Y. Sugiura, Y. Tachikawa, Y. Nagasawa, N. Tada and A. Itoh
RSC Advances 2015 vol. 5(Issue 87) pp:70883-70886
Publication Date(Web):06 Aug 2015
DOI:10.1039/C5RA13269J
We developed a synthetic method toward benzoyl cyanide through aerobic photooxidation of benzyl cyanide in the presence of carbon tetrabromide under visible light irradiation with fluorescent lamps.
Co-reporter:A. Fujiya, T. Nobuta, E. Yamaguchi, N. Tada, T. Miura and A. Itoh
RSC Advances 2015 vol. 5(Issue 49) pp:39539-39543
Publication Date(Web):16 Apr 2015
DOI:10.1039/C5RA05155J
We report an aerobic photooxidative direct asymmetric aldol reaction using water as the solvent. In this reaction, primary benzyl alcohols are oxidized into benzaldehydes under an oxygen atmosphere using anthraquinone-2-sodium sulfonate monohydrate as an organophotocatalyst. Stereoselective aldol reactions then proceed using a proline-type organocatalyst.
Co-reporter:Masanori Tanaka, Yuji Kamito, Cui Lei, Norihiro Tada, Akichika Itoh
Tetrahedron Letters 2015 Volume 56(Issue 43) pp:5886-5888
Publication Date(Web):21 October 2015
DOI:10.1016/j.tetlet.2015.09.008
We developed the aerobic photooxidative bromination of aromatic compounds using carbon tetrabromide in the presence of anthraquinone-2-carboxylic acid under visible light irradiation.
Co-reporter:Tomoaki Yamaguchi, Yasuhisa Kudo, Shin-ichi Hirashima, Eiji Yamaguchi, Norihiro Tada, Tsuyoshi Miura, Akichika Itoh
Tetrahedron Letters 2015 Volume 56(Issue 15) pp:1973-1975
Publication Date(Web):8 April 2015
DOI:10.1016/j.tetlet.2015.02.104
A convenient metal-free oxidation protocol of various cyclic acetals with molecular oxygen and anthraquinone-2-carboxylic acid under visible light irradiation by a fluorescent lamp afforded their corresponding hydroxyalkyl esters.
Co-reporter:Atsumasa Kariya, Tomoaki Yamaguchi, Tomoya Nobuta, Norihiro Tada, Tsuyoshi Miura and Akichika Itoh
RSC Advances 2014 vol. 4(Issue 25) pp:13191-13194
Publication Date(Web):28 Feb 2014
DOI:10.1039/C3RA47863G
The synthesis of β-hydroxy sulfones from alkenes and sodium sulfinates under aerobic oxidative conditions was achieved in the presence of a catalytic amount of molecular iodine. Molecular oxygen in air serves as the terminal oxidant and the catalytic amount of molecular iodine acts as the sulfonyl radical initiator and peroxide reductant.
Co-reporter:Izuho Itoh, Yoko Matsusaki, Akitoshi Fujiya, Norihiro Tada, Tsuyoshi Miura, Akichika Itoh
Tetrahedron Letters 2014 Volume 55(Issue 20) pp:3160-3162
Publication Date(Web):14 May 2014
DOI:10.1016/j.tetlet.2014.03.123
Co-reporter:Tomoya Nobuta, Norihiro Tada, Akitoshi Fujiya, Atsumasa Kariya, Tsuyoshi Miura, and Akichika Itoh
Organic Letters 2013 Volume 15(Issue 3) pp:574-577
Publication Date(Web):January 18, 2013
DOI:10.1021/ol303389t
A useful method for molecular iodine catalyzed oxidative C–C bond formation between tertiary amines and a carbon nucleophile using hydrogen peroxide as the terminal oxidant is reported. This is the first report of a molecular iodine catalyzed cross-dehydrogenative coupling (CDC) reaction between two sp3 C–H bonds.
Co-reporter:Lei Cui;Yoko Matusaki;Norihiro Tada;Tsuyoshi Miura;Bunji Uno
Advanced Synthesis & Catalysis 2013 Volume 355( Issue 11-12) pp:2203-2207
Publication Date(Web):
DOI:10.1002/adsc.201300199
Co-reporter:Tomoya Nobuta, Akitoshi Fujiya, Tomoaki Yamaguchi, Norihiro Tada, Tsuyoshi Miura and Akichika Itoh
RSC Advances 2013 vol. 3(Issue 26) pp:10189-10192
Publication Date(Web):01 May 2013
DOI:10.1039/C3RA41850B
This paper reports a useful method for molecular-iodine-catalyzed aerobic photooxidative C–C bond formation between tertiary amines and carbon nucleophiles. This reaction provides a practical method for C–C bond formation through the use of molecular iodine, harmless visible light irradiation, and molecular oxygen as the terminal oxidant.
Co-reporter:Lei Cui, Sohei Furuhashi, Yuma Tachikawa, Norihiro Tada, Tsuyoshi Miura, Akichika Itoh
Tetrahedron Letters 2013 Volume 54(Issue 2) pp:162-165
Publication Date(Web):9 January 2013
DOI:10.1016/j.tetlet.2012.10.119
We developed an efficient method for the generation of hydrogen peroxide by aerobic photooxidation of 2-propanol using anthraquinone-2-carboxylic acid and molecular oxygen in air and visible light from fluorescent lamps. One-pot epoxidation of α,β-unsaturated ketones using the generated hydrogen peroxide is also reported.
Co-reporter:Yuma Tachikawa, Lei Cui, Yoko Matsusaki, Norihiro Tada, Tsuyoshi Miura, Akichika Itoh
Tetrahedron Letters 2013 Volume 54(Issue 46) pp:6218-6221
Publication Date(Web):13 November 2013
DOI:10.1016/j.tetlet.2013.09.015
We developed direct aerobic photooxidation of 1,3-diketones to corresponding carboxylic acids in the presence of a catalytic amount of 2-chloroanthraquinone under visible light irradiation from fluorescent lamps.
Co-reporter:Norihiro Tada, Takafumi Ishigami, Lei Cui, Kazunori Ban, Tsuyoshi Miura, Akichika Itoh
Tetrahedron Letters 2013 Volume 54(Issue 3) pp:256-258
Publication Date(Web):16 January 2013
DOI:10.1016/j.tetlet.2012.11.014
We developed aerobic photooxidative oxylactonization of oxocarboxylic acids catalyzed by calcium iodide using molecular oxygen as the terminal oxidant under photo irradiation.
Co-reporter:Tomoaki Yamaguchi, Yoko Matsusaki, Norihiro Tada, Tsuyoshi Miura and Akichika Itoh
Photochemical & Photobiological Sciences 2013 vol. 12(Issue 3) pp:417-420
Publication Date(Web):12 Nov 2012
DOI:10.1039/C2PP25345C
We developed an aerobic photooxidative cleavage of epoxides to carboxylic acids using a catalytic quantity of magnesium bromide and molecular oxygen as the terminal oxidant, under photoirradiation with a high-pressure mercury lamp.
Co-reporter:Norihiro Tada, Lei Cui, Takafumi Ishigami, Kazunori Ban, Tsuyoshi Miura, Bunji Uno and Akichika Itoh
Green Chemistry 2012 vol. 14(Issue 11) pp:3007-3009
Publication Date(Web):04 Sep 2012
DOI:10.1039/C2GC36238D
We developed efficient aerobic photooxidative oxylactonizations of oxocarboxylic acids promoted by trifluoroacetic anhydride with molecular oxygen as the terminal oxidant in the fluorous solvent FC-72.
Co-reporter:Tomoya Nobuta, Akitoshi Fujiya, Shin-ichi Hirashima, Norihiro Tada, Tsuyoshi Miura, Akichika Itoh
Tetrahedron Letters 2012 Volume 53(Issue 39) pp:5306-5308
Publication Date(Web):26 September 2012
DOI:10.1016/j.tetlet.2012.07.091
We report a useful method for the facile synthesis of aromatic esters from benzyl alcohols with molecular oxygen and catalytic tetrabromomethane in alcohol under visible light irradiation with a fluorescent lamp. This is the first metal-free reaction using molecular oxygen as the terminal oxidant.
Co-reporter:Norihiro Tada, Yuki Ikebata, Tomoya Nobuta, Shin-ichi Hirashima, Tsuyoshi Miura and Akichika Itoh
Photochemical & Photobiological Sciences 2012 vol. 11(Issue 4) pp:616-619
Publication Date(Web):01 Feb 2012
DOI:10.1039/C2PP05387J
This paper reports a useful method for facile direct syntheses of aromatic methyl esters from methyl aromatics by aerobic photo-oxidation using anthraquinone-2,3-dicarboxylic acid as an organophotocatalyst.
Co-reporter:Lei Cui, Norihiro Tada, Hiroaki Okubo, Tsuyoshi Miura and Akichika Itoh
Green Chemistry 2011 vol. 13(Issue 9) pp:2347-2350
Publication Date(Web):18 Jul 2011
DOI:10.1039/C1GC15437K
We developed an efficient dihydroperoxidation protocol of various carbonyl compounds with molecular oxygen and anthraquinone in 2-propanol under visible light irradiation with a fluorescent lamp, which produced corresponding gem-dihydroperoxides in high yields.
Co-reporter:Norihiro Tada, Kasumi Hattori, Tomoya Nobuta, Tsuyoshi Miura and Akichika Itoh
Green Chemistry 2011 vol. 13(Issue 7) pp:1669-1671
Publication Date(Web):17 May 2011
DOI:10.1039/C1GC15154A
We report a useful method for a facile synthesis of carboxylic acids from methyl aromatics by aerobic photooxidation using VIS irradiation and easily handled 2-chloroanthraquinone as organic catalysts under mild conditions such as an air atmosphere and ambient pressure and temperature. This is a more environmentally benign oxidation than previous methods, which require drastic reaction conditions.
Co-reporter:Tomoya Nobuta, Shin-ichi Hirashima, Norihiro Tada, Tsuyoshi Miura, and Akichika Itoh
Organic Letters 2011 Volume 13(Issue 10) pp:2576-2579
Publication Date(Web):April 27, 2011
DOI:10.1021/ol200681k
A one-pot synthetic protocol of acetophenones from styrenes with molecular oxygen, visible light, and molecular iodine is reported. This procedure involves aerobic photo-oxidation and deiodination in one pot and provides the first report of metal-free direct syntheses of acetophenones from styrenes.
Co-reporter:Tomoya Nobuta, Norihiro Tada, Kasumi Hattori, Shin-ichi Hirashima, Tsuyoshi Miura, Akichika Itoh
Tetrahedron Letters 2011 Volume 52(Issue 8) pp:875-877
Publication Date(Web):23 February 2011
DOI:10.1016/j.tetlet.2010.12.029
We report a useful method for facile aerobic photo-oxidative synthesis of α-diketones from alkynes with MgBr2·OEt2. This procedure provides a practical synthetic method of α-diketones using easily handled bromine sources, harmless visible light, and molecular oxygen as terminal oxidant.We report a useful method for facile aerobic photo-oxidative synthesis of α-diketones from alkynes with MgBr2·OEt2. This procedure provides a practical synthetic method of α-diketones using easily handled bromine sources, harmless visible light, and molecular oxygen as terminal oxidant.
Co-reporter:Norihiro Tada, Kazunori Ban, Takafumi Ishigami, Tomoya Nobuta, Tsuyoshi Miura, Akichika Itoh
Tetrahedron Letters 2011 Volume 52(Issue 29) pp:3821-3824
Publication Date(Web):20 July 2011
DOI:10.1016/j.tetlet.2011.05.077
The facile synthesis of α,α-dibromoacetophenones from ethyl-substituted aromatics by aerobic photooxidation has been developed. This synthetic method achieves oxidative dibromination of aromatic ethyl groups by using inexpensive and easily handled bromine sources, harmless visible light and molecular oxygen.
Co-reporter:Naohiko Kanai, Hiroki Nakayama, Norihiro Tada and Akichika Itoh
Organic Letters 2010 Volume 12(Issue 9) pp:1948-1951
Publication Date(Web):March 29, 2010
DOI:10.1021/ol1003675
It was found that β-ketoesters were directly transformed to the corresponding α-hydroxymalonic esters, tartronic esters, with molecular oxygen catalyzed by calcium iodide under visible light irradiation from fluorescent lamp. This reaction includes tandem oxidation/rearrangement and has received much attention from the viewpoint of reduction of energy consumption, labor, and solvents.
Co-reporter:Shin-ichi Hirashima, Tomoya Nobuta, Norihiro Tada, Tsuyoshi Miura and Akichika Itoh
Organic Letters 2010 Volume 12(Issue 16) pp:3645-3647
Publication Date(Web):July 29, 2010
DOI:10.1021/ol1014575
A useful method for facile synthesis of aromatic methyl esters from methyl aromatics via dimethyl acetals by aerobic photo-oxidation using inexpensive and easily handled CBr4 as catalyst is reported. This is the first example for direct preparation of the corresponding aromatic methyl esters from methyl aromatics.
Co-reporter:Norihiro Tada, Lei Cui, Hiroaki Okubo, Tsuyoshi Miura and Akichika Itoh
Chemical Communications 2010 vol. 46(Issue 10) pp:1772-1774
Publication Date(Web):14 Jan 2010
DOI:10.1039/B917056A
gem-Dihydroperoxides were easily obtained from the corresponding carbonyl compounds in high yields through a catalyst-free method with aqueous H2O2 (35%) in 1,2-dimethoxyethane at room temperature.
Co-reporter:Norihiro Tada;Lei Cui;Hiroaki Okubo;Tsuyoshi Miura
Advanced Synthesis & Catalysis 2010 Volume 352( Issue 14-15) pp:2383-2386
Publication Date(Web):
DOI:10.1002/adsc.201000357
Abstract
A new efficient dihydroperoxidation protocol of a wide variety of carbonyl compounds with molecular oxygen, anthracene, and 2-propanol under light irradiation afforded their corresponding gem-dihydroperoxides in high yields.
Co-reporter:Norihiro Tada, Kazunori Ban, Shin-ichi Hirashima, Tsuyoshi Miura and Akichika Itoh
Organic & Biomolecular Chemistry 2010 vol. 8(Issue 20) pp:4701-4704
Publication Date(Web):25 Aug 2010
DOI:10.1039/C0OB00101E
The direct synthesis of α-bromoketones from alkylarenes by aerobic photooxidation with hydrobromic acid is reported. The key success for this direct oxidative reaction is due to control of bromination with acetic acid and ethanol, which are generated in situ by solvolysis of ethyl acetate in the course of the reaction.
Co-reporter:Norihiro Tada, Kazunori Ban, Momoko Yoshida, Shin-ichi Hirashima, Tsuyoshi Miura, Akichika Itoh
Tetrahedron Letters 2010 Volume 51(Issue 47) pp:6098-6100
Publication Date(Web):24 November 2010
DOI:10.1016/j.tetlet.2010.09.021
Benzylamides were found to be oxidized to their corresponding diacylamines in the presence of molecular oxygen, catalytic 48% aq HBr, and Ca(OH)2 under visible light irradiation of a fluorescent lamp.Benzylamides were found to be oxidized to their corresponding diacylamines in the presence of molecular oxygen, catalytic 48% aq HBr, and Ca(OH)2 under visible light irradiation of a fluorescent lamp.
Co-reporter:Tomoya Nobuta, Shin-ichi Hirashima, Norihiro Tada, Tsuyoshi Miura, Akichika Itoh
Tetrahedron Letters 2010 Volume 51(Issue 34) pp:4576-4578
Publication Date(Web):25 August 2010
DOI:10.1016/j.tetlet.2010.06.120
We report a useful method for facile aerobic photo-oxidative synthesis of α,α-dibromoacetophenones from aromatic alkynes with 48% aq HBr. This method provides the synthesis of α,α-dibromoacetophenones using inexpensive and easily handled bromine sources, harmless visible light, and molecular oxygen.
Co-reporter:Shin-ichi Hirashima, Yasuhisa Kudo, Tomoya Nobuta, Norihiro Tada, Akichika Itoh
Tetrahedron Letters 2009 50(30) pp: 4328-4330
Publication Date(Web):
DOI:10.1016/j.tetlet.2009.05.012
Co-reporter:Shin-ichi Hirashima and Akichika Itoh
Green Chemistry 2007 vol. 9(Issue 4) pp:318-320
Publication Date(Web):11 Jan 2007
DOI:10.1039/B613931K
A catalytic amount of magnesium bromide diethyl etherate enables us to carry out the aerobic photo-oxidation of alcohols under irradiation of VIS from a general-purpose fluorescent lamp. Aliphatic primary alcohols, secondary alcohols and benzyl alcohols generally afforded the carboxylic acids directly in good to high yield. The bromine radical is thought to be generated in situ by continuous aerobic photo-oxidation of the bromo anion from MgBr2·Et2O, and to effect this oxidation reaction.
Co-reporter:Shin-ichi Hirashima and Akichika Itoh
Photochemical & Photobiological Sciences 2007 vol. 6(Issue 5) pp:521-524
Publication Date(Web):12 Apr 2007
DOI:10.1039/B702703F
A catalytic amount of magnesium bromide diethyl etherate (MgBr2·Et2O) enables us to carry out the aerobic photo-oxidation of a methyl group at the aromatic nucleus to the corresponding carboxylic acid in high yield under irradiation of VIS from a general-purpose fluorescent lamp. The bromine radical is thought to be generated in situ by continuous aerobic photo-oxidation of the bromine anion from MgBr2·Et2O, and to effect this oxidation reaction.
Co-reporter:Akichika Itoh, Shouei Hashimoto, Kiyoto Kuwabara, Tomohiro Kodama and Yukio Masaki
Green Chemistry 2005 vol. 7(Issue 12) pp:830-832
Publication Date(Web):31 Oct 2005
DOI:10.1039/B511780A
A useful method for the aerobic oxidation of alcohols directly to the corresponding carboxylic acid or ketone with combination of sodium bromide and Amberlyst 15 (safe and inexpensive reagents) under solar radiation is reported.
Co-reporter:Norihiro Tada, Kazunori Ban, Shin-ichi Hirashima, Tsuyoshi Miura and Akichika Itoh
Organic & Biomolecular Chemistry 2010 - vol. 8(Issue 20) pp:NaN4704-4704
Publication Date(Web):2010/08/25
DOI:10.1039/C0OB00101E
The direct synthesis of α-bromoketones from alkylarenes by aerobic photooxidation with hydrobromic acid is reported. The key success for this direct oxidative reaction is due to control of bromination with acetic acid and ethanol, which are generated in situ by solvolysis of ethyl acetate in the course of the reaction.
Co-reporter:Norihiro Tada, Lei Cui, Hiroaki Okubo, Tsuyoshi Miura and Akichika Itoh
Chemical Communications 2010 - vol. 46(Issue 10) pp:NaN1774-1774
Publication Date(Web):2010/01/14
DOI:10.1039/B917056A
gem-Dihydroperoxides were easily obtained from the corresponding carbonyl compounds in high yields through a catalyst-free method with aqueous H2O2 (35%) in 1,2-dimethoxyethane at room temperature.