Shin Kamijo

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Organization: Yamaguchi University , Japan

Department: Graduate School of Science and Engineering

Title: Associate Professor(PhD)

TOPICS

Organic Chemistry

Formylation

Chemicals
References

Synthesis of Alkylated Pyrimidines via Photoinduced Coupling Using Benzophenone as a Mediator

Co-reporter:Shin KamijoKaori Kamijo, Toshihiro Murafuji

The Journal of Organic Chemistry 2017 Volume 82(Issue 5) pp:

Publication Date(Web):February 14, 2017

DOI:10.1021/acs.joc.6b03058

The synthesis of alkylated pyrimidines was achieved via benzophenone-mediated photoinduced coupling between saturated heterocycles and sulfonylpyrimidines. The pyrimidine ring was selectively introduced at the nonacidic C(sp3)–H bond proximal to heteroatoms including oxygen, nitrogen, and sulfur. This is a coupling reaction mediated solely by photoexcited benzophenone, an organic molecule, without the aid of any metallic catalysts or reagents.

Alkylation of Nonacidic C(sp3)–H Bonds by Photoinduced Catalytic Michael-Type Radical Addition

Co-reporter:Shin Kamijo, Go Takao, Kaori Kamijo, Teruo Tsuno, Katsuya Ishiguro, and Toshihiro Murafuji

Organic Letters 2016 Volume 18(Issue 19) pp:4912-4915

Publication Date(Web):September 26, 2016

DOI:10.1021/acs.orglett.6b02391

Photoinduced catalytic Michael-type radical addition was achieved via olefin insertion into a nonacidic C(sp3)–H bond, utilizing 2-chloroanthraquinone as a C–H bond-cleaving catalyst and 1,1-bis(phenylsulfonyl)ethylene as an olefinic substrate. The present radical protocol allows carbon chain extension stemming from nonacidic C–H bonds, which complements alkylation at acidic C–H bonds under ionic conditions and installs the active methine site that acts as a versatile synthetic handle for further transformations.

Aryl Ketone Catalyzed Radical Allylation of C(sp3)–H Bonds under Photoirradiation

Co-reporter:Shin KamijoKaori Kamijo, Kiyotaka Maruoka, Toshihiro Murafuji

Organic Letters 2016 Volume 18(Issue 24) pp:6516-6519

Publication Date(Web):December 8, 2016

DOI:10.1021/acs.orglett.6b03586

The catalytic introduction of an allyl group at nonacidic C(sp3)–H bonds was achieved under photoirradiation, in which 1,2-bis(phenylsulfonyl)-2-propene acts as an allyl source and 5,7,12,14-pentacenetetrone (PT) works as a C–H bond-cleaving catalyst. A variety of substances, including alkanes, carbamates, ethers, sulfides, and alcohols, were chemoselectively allylated in a single step under neutral conditions. The present transformation is catalyzed solely by an organic molecule, PT, and proceeds smoothly even under visible light irradiation (425 nm) in the case of alkanes as a starting substance.

Two-directional carbon chain elongation via the consecutive 1,4-addition of allyl malononitrile and the Cope rearrangement on an alkynoate platform

Co-reporter:Shin Kamijo, Kaori Kamijo, Daiki Magarifuchi, Ryota Ozawa, Keisuke Tao, Toshihiro Murafuji

Tetrahedron Letters 2016 Volume 57(Issue 1) pp:137-140

Publication Date(Web):6 January 2016

DOI:10.1016/j.tetlet.2015.11.081

A one-pot procedure for the regioselective introduction of two different three-carbon units, allyl and malononitrile functionalities, to C–C triple bonds was established. The transformation proceeds through the phosphine-catalyzed 1,4-addition of allyl malononitrile to the alkynoate and the Cope rearrangement with microwave heating, achieving two-directional carbon chain elongation on the alkynoate platform. The operational simplicity, succinct carbon skeletal construction, and high atom economy should make the present procedure appealing for the synthesis of structurally complex organic molecules.

Photo-induced Substitutive Introduction of the Aldoxime Functional Group to Carbon Chains: A Formal Formylation of Non-Acidic C(sp3)H Bonds

Co-reporter:Dr. Shin Kamijo;Go Takao;Kaori Kamijo;Masaki Hirota;Dr. Keisuke Tao;Dr. Toshihiro Murafuji

Angewandte Chemie 2016 Volume 128( Issue 33) pp:9847-9851

Publication Date(Web):

DOI:10.1002/ange.201603810

Abstract

A photo-induced substitutive introduction of an aldoxime functional group to carbon chains was achieved using photo-excited 4-benzoylpyridine as a C(sp³)−H bond cleaving agent and arylsulfonyl oxime as an aldoxime precursor. The non-acidic C−H bonds in various substances, including cycloalkanes, ethers, azacycles, and cyclic sulfides, were chemoselectively converted at ambient temperature under neutral conditions. The present transformation is a formal formylation of non-acidic C(sp³)−H bonds in a single step.

Photo-induced Substitutive Introduction of the Aldoxime Functional Group to Carbon Chains: A Formal Formylation of Non-Acidic C(sp3)H Bonds

Co-reporter:Dr. Shin Kamijo;Go Takao;Kaori Kamijo;Masaki Hirota;Dr. Keisuke Tao;Dr. Toshihiro Murafuji

Angewandte Chemie International Edition 2016 Volume 55( Issue 33) pp:9695-9699

Publication Date(Web):

DOI:10.1002/anie.201603810

Abstract

Photoinduced Oxidation of Secondary Alcohols Using 4-Benzoylpyridine as an Oxidant

Co-reporter:Shin Kamijo, Keisuke Tao, Go Takao, Hiroshi Tonoda, and Toshihiro Murafuji

Organic Letters 2015 Volume 17(Issue 13) pp:3326-3329

Publication Date(Web):June 22, 2015

DOI:10.1021/acs.orglett.5b01550

Photoinduced oxidation of secondary alcohols to ketones was achieved by utilizing an equimolar amount of 4-benzoylpyridine as an oxidant. This transformation proceeds at ambient temperature and exhibits high compatibility with polar functionalities including benzoyl, silyl, and methoxymethyl alcohol protecting groups as well as tosyloxy, bromo, sulfonyl, carbamate, ester, and carboxylic acid units. The present oxidation is solely promoted by the action of organic molecules without the aid of metallic reagents.

Ether derivatization via two-step protocol comprised of photochemical ethereal C–H bond chlorination and nucleophilic substitution

Co-reporter:Shin Kamijo, Keisuke Tao, Go Takao, Hironori Murooka, Toshihiro Murafuji

Tetrahedron Letters 2015 Volume 56(Issue 14) pp:1904-1907

Publication Date(Web):1 April 2015

DOI:10.1016/j.tetlet.2015.02.102

A two-step protocol has been developed for ether derivatization introducing oxygen-, sulfur-, and carbon-functionalities. The present protocol comprises photochemical chlorination of ethereal C(sp3)–H bond for preparation of chlorinated ethers as common synthetic intermediates, and nucleophilic substitution of the installed chlorine moiety for construction of various ether derivatives. These two reactions can be conducted sequentially in a single flask, thus the newly developed method offers a one-pot and unified procedure for ether derivatization with attachment of various functionalities at the α-position.

Photochemically induced radical alkenylation of C(sp3)–H bonds

Co-reporter:Yuuki Amaoka, Masanori Nagatomo, Mizuki Watanabe, Keisuke Tao, Shin Kamijo and Masayuki Inoue

Chemical Science 2014 vol. 5(Issue 11) pp:4339-4345

Publication Date(Web):2014/06/30

DOI:10.1039/C4SC01631A

The direct alkenylation of C(sp3)–H bonds was achieved by employing benzophenone and 1,2-bis(phenylsulfonyl)ethylene under photo-irradiation conditions. This simple metal-free reaction enables the substitution of heteroatom-substituted methine, methylene and aliphatic C(sp3)–H bonds by (E)-sulfonylalkene units in a highly chemoselective manner. The derived sulfonylalkenes were further converted in a single step to the prenyl derivatives via a second photo-induced radical substitution and to the pyrrole derivatives via cyclization and aromatization steps. The present protocol thus serves as an efficient method for the direct extension of carbon skeletons for the synthesis of structurally complex natural products and pharmaceuticals.

Photoinduced sulfonylation of cyclic ethers

Co-reporter:Shin Kamijo, Masaki Hirota, Keisuke Tao, Mizuki Watanabe, Toshihiro Murafuji

Tetrahedron Letters 2014 Volume 55(Issue 40) pp:5551-5554

Publication Date(Web):1 October 2014

DOI:10.1016/j.tetlet.2014.08.011

A one-step preparation of α-sulfonylated cyclic ethers has been achieved via the intermolecular sulfonylation of ethereal CH bonds. In this process, the chemoselective cleavage of the ethereal CH bond was achieved by hydrogen abstraction with photo-excited benzophenone, and the sulfonyl unit was provided by sulfonyl chloride. This protocol allows a direct transformation of ethereal C(sp3)H bonds to C(sp3)SO2R bonds under photo-irradiation conditions at room temperature.

Photochemically induced radical alkenylation of C(sp3)–H bonds

Co-reporter:Yuuki Amaoka, Masanori Nagatomo, Mizuki Watanabe, Keisuke Tao, Shin Kamijo and Masayuki Inoue

Chemical Science (2010-Present) 2014 - vol. 5(Issue 11) pp:NaN4345-4345

Publication Date(Web):2014/06/30

DOI:10.1039/C4SC01631A