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1

A protocol for visible light promoted desulfonylation reactions utilizing catalytic benzimidazolium aryloxide betaines and stoichiometric hydride donor reagents

Hasegawa, Eietsu, Tanaka, Tsukasa, Izumiya, Norihiro, Kiuchi, Takehiro, Ooe, Yuuki, Iwamoto, Hajime, Takizawa, Shin-ya, Murata, Shigeru

Journal:

Journal of Organic Chemistry

Year:

2020

Language:

english

File:

PDF, 618 KB

english, 2020

2

ChemInform Abstract: Reductive Transformation of α,β-Epoxy Ketones and Other Compounds Promoted Through Photoinduced Electron Transfer Processes with 1,3-Dimethyl-2-phenylbenzimidazoline (DMPBI).

Eietsu Hasegawa, Akira Yoneoka, Kumiko Suzuki, Teru Kato, Takashi Kitazume, Kazuhiro Yanagi

Journal:

Year:

2000

File:

PDF, 39 KB

2000

3

ChemInform Abstract: 1,3-Dimethyl-2-phenylbenzimidazoline (DMPBI)—Acetic Acid: An Effective Reagent System for Photoinduced Reductive Transformation of α,β-Epoxy Ketones to β-Hydroxy Ketones.

Eietsu Hasegawa, Naoki Chiba, Aiko Nakajima, Kumiko Suzuki, Akira Yoneoka, Kazuki Iwaya

Journal:

Year:

2001

File:

PDF, 38 KB

2001

4

Samarium Diiodide Promoted Intramolecular Ketone—Ester Coupling Reaction: Novel Cyclization and Ring Expansion Pathway.

Kazuki Iwaya, Momoe Nakamura, Eietsu Hasegawa

Journal:

Year:

2002

File:

PDF, 31 KB

2002

5

Changeable Reactivity of Ketyl Radicals Derived from 2-Bromomethyl-2-(3-butenyl)benzocyclic-1-alkanones Depending on Electron Transfer Conditions Employed.

Eietsu Hasegawa, Shinya Takizawa, Kazuki Iwaya, Miyuki Kurokawa, Naoki Chiba, Keiko Yamamichi

Journal:

Year:

2002

File:

PDF, 32 KB

2002

6

2-Hydroxyphenyl-1,3-dimethylbenzimidazolines. Formal Two Hydrogen Atom-Donors for Photoinduced Electron Transfer Reactions.

Eietsu Hasegawa, Naoki Chiba, Tomoya Takahashi, Shinya Takizawa, Takashi Kitayama, Toshio Suzuki

Journal:

Year:

2004

File:

PDF, 126 KB

2004

7

Photoinduced Electron Transfer Reactions of Oxiranes and Epoxy Ketones

Eietsu Hasegawa, Masaki Kamata

Journal:

Year:

2004

File:

PDF, 51 KB

2004

8

ChemInform Abstract: Benzimidazoline-Dimethoxypyrene. An Effective Promoter System for Photoinduced Electron Transfer Promoted Reductive Transformations of Organic Compounds.

Eietsu Hasegawa, Harumi Hirose, Kosuke Sasaki, Shinya Takizawa, Takayuki Seida, Naoki Chiba

Journal:

Year:

2009

File:

PDF, 33 KB

2009

9

ChemInform Abstract: Remarkable Enhancement Effect of Potassium tert-Butoxide/THF Solution in Base-Induced Sommelet—Hauser Rearrangements.

Eiji Tayama, Keisuke Takedachi, Hajime Iwamoto, Eietsu Hasegawa

Journal:

Year:

2011

File:

PDF, 36 KB

2011

10

ChemInform Abstract: Application of Biphasic Reaction Procedure Using Ferric Chloride Dissolved in an Imidazolium Salt and Benzotrifluoride (FeIm-BTF Procedure) to Aza-Prins Cyclization Reaction.

Eietsu Hasegawa, Nohara Hiroi, Chika Osawa, Eiji Tayama, Hajime Iwamoto

Journal:

Year:

2011

File:

PDF, 32 KB

2011

11

ChemInform Abstract: Copper(II) Triflate Catalyzed Intermolecular Aromatic Substitution of N,N-Disubstituted Anilines with Diazo Esters.

Eiji Tayama, Tomoyo Yanaki, Hajime Iwamoto, Eietsu Hasegawa

Journal:

Year:

2011

File:

PDF, 32 KB

2011

12

ChemInform Abstract: Asymmetric α-2-Tosylvinylation of in situ Generated N-2-Tosylvinyl Proline-Derived Ammonium Ylides.

Tomohito Igarashi, Eiji Tayama, Hajime Iwamoto, Eietsu Hasegawa

Journal:

Year:

2011

File:

PDF, 32 KB

2011

13

Copper(II) Triflate Catalyzed Intermolecular Aromatic Substitution of N,N-Disubstituted Anilines with Diazo Esters

Eiji Tayama, Tomoyo Yanaki, Hajime Iwamoto, Eietsu Hasegawa

Journal:

European Journal of Organic Chemistry

Year:

2010

Language:

english

File:

PDF, 199 KB

english, 2010

14

Photocyclization reactions. Part 6. Solvent and substituent effects in the synthesis of dihydrobenzofuranols using photocyclization of 2-alkoxybenzophenones and ethyl 2-benzoylphenoxyacetates

Essam Mohamed Sharshira, Mutsuo Okamura, Eietsu Hasegawa, Takaaki Horaguchi

Journal:

Journal of Heterocyclic Chemistry

Year:

1997

File:

PDF, 622 KB

1997

15

Deprotection of 1,3-dithianes by antimony pentachloride via single electron transfer processes

Masaki Kamata, Hisashi Otogawa, Eietsu Hasegawa

Journal:

Tetrahedron Letters

Year:

1991

Language:

english

File:

PDF, 164 KB

english, 1991

16

Reactions of 1-bromo-2,3-epoxypropane with samarium diiodide: First observation of carbon-carbon bond cleavage of oxiranylmethyl radical under the single electron transfer conditions

Eietsu Hasegawa, Masanori Takahashi, Takaaki Horaguchi

Journal:

Tetrahedron Letters

Year:

1995

Language:

english

File:

PDF, 212 KB

english, 1995

17

Electron transfer induced stereoselective cyclization of 2,2-disubstituted dibenzoylmethane to anti-1,2-cyclopropanediol

Eietsu Hasegawa, Hideyuki Katagi, Daisuke Nakagawa, Takaaki Horaguchi, Shyoji Tanaka, Yoshiro Yamashita

Journal:

Tetrahedron Letters

Year:

1995

Language:

english

File:

PDF, 251 KB

english, 1995

18

Aminium salt promoted catalytic substitution reactions of acetals with silylated nucleophiles

Masaki Kamata, Yukiko Yokoyama, Natsuko Karasawa, Mitsuaki Kato, Eietsu Hasegawa

Journal:

Tetrahedron Letters

Year:

1996

Language:

english

File:

PDF, 220 KB

english, 1996

19

Photoinduced electron transfer reactions of α,β-epoxy ketones with 2-phenyl-N,N-dimethylbenzimidazoline (PDMBI): Significant water effect on the reaction pathway

Eietsu Hasegawa, Teru Kato, Takashi Kitazume, Kazuhiro Yanagi, Kazuya Hasegawa, Takaaki Horaguchi

Journal:

Tetrahedron Letters

Year:

1996

Language:

english

File:

PDF, 232 KB

english, 1996

20

Pyrylium salt promoted substitution reactions of acetals with various silylated nucleophiles

Masaki Kamata, Satoshi Nagai, Mitsuaki Kato, Eietsu Hasegawa

Journal:

Tetrahedron Letters

Year:

1996

Language:

english

File:

PDF, 250 KB

english, 1996

21

Photoinduced electron-transfer systems consisting of electron-donating pyrenes or anthracenes and benzimidazolines for reductive transformation of carbonyl compounds

Eietsu Hasegawa, Shinya Takizawa, Takayuki Seida, Akira Yamaguchi, Naoto Yamaguchi, Naoki Chiba, Tomoya Takahashi, Hiroshi Ikeda, Kimio Akiyama

Journal:

Year:

2006

Language:

english

File:

PDF, 347 KB

english, 2006

22

Tris(trimethylsilyl)silane promoted radical reaction and electron-transfer reaction in benzotrifluoride

Eietsu Hasegawa, Yuki Ogawa, Koji Kakinuma, Hiroyuki Tsuchida, Emi Tosaka, Shinya Takizawa, Hiroyasu Muraoka, Tomoko Saikawa

Journal:

Year:

2008

Language:

english

File:

PDF, 311 KB

english, 2008

23

Novel biphasic reaction system of ferric chloride dissolved imidazolium hexafluorophosphate and benzotrifluoride: application to electron transfer reaction of cyclopropyl silyl ethers

Hiroyuki Tsuchida, Eietsu Hasegawa

Journal:

Year:

2010

Language:

english

File:

PDF, 330 KB

english, 2010

24

Remarkable enhancement effect of potassium tert-butoxide/THF solution in base-induced Sommelet–Hauser rearrangements

Eiji Tayama, Keisuke Takedachi, Hajime Iwamoto, Eietsu Hasegawa

Journal:

Year:

2010

Language:

english

File:

PDF, 364 KB

english, 2010

25

Novel transformation of 2-substituted alkyl 1-indanone-2-acetates to 6-substituted 3,4-benzotropolones through sequential reduction and oxidation processes using Sm(II) and Ce(IV) salts

Kazuki Iwaya, Mutsuko Tamura, Momoe Nakamura, Eietsu Hasegawa

Journal:

Tetrahedron Letters

Year:

2003

Language:

english

File:

PDF, 177 KB

english, 2003

26

The first example of samarium diiodide-promoted intramolecular ketone–ester coupling of ketones tethering acyloxyalkyl side chains producing 2-hydroxy cyclic hemiacetals

Eietsu Hasegawa, Kentaro Okamoto, Naoko Tanikawa, Momoe Nakamura, Kazuki Iwaya, Takashi Hoshi, Toshio Suzuki

Journal:

Tetrahedron Letters

Year:

2006

Language:

english

File:

PDF, 124 KB

english, 2006

27

Application of biphasic reaction procedure using ferric chloride dissolved in an imidazolium salt and benzotrifluoride (FeIm-BTF procedure) to aza-Prins cyclization reaction

Eietsu Hasegawa, Nohara Hiroi, Chika Osawa, Eiji Tayama, Hajime Iwamoto

Journal:

Tetrahedron Letters

Year:

2010

Language:

english

File:

PDF, 292 KB

english, 2010

28

Asymmetric α-2-tosylvinylation of in situ-generated N-2-tosylvinyl proline-derived ammonium ylides

Tomohito Igarashi, Eiji Tayama, Hajime Iwamoto, Eietsu Hasegawa

Journal:

Tetrahedron Letters

Year:

2011

Language:

english

File:

PDF, 248 KB

english, 2011

29

Pyrylium salt sensitized photochemical deprotections of dithioacetals and ketals

Masaki Kamata, Yukiko Murakami, Yasuko Tamagawa, Mitsuaki Kato, Eietsu Hasegawa

Journal:

Year:

1994

Language:

english

File:

PDF, 431 KB

english, 1994

30

Rate constants for the reactions of primary alkyl radicals with SmI2 in THF/HMPA

Eietsu Hasegawa, Dennis P. Curran

Journal:

Tetrahedron Letters

Year:

1993

Language:

english

File:

PDF, 361 KB

english, 1993

31

Photosensitized oxygenation reactions of 1,3-dithianes through cooperative single electron transfer pathway and singlet oxygen pathway

Masaki Kamata, Masao Sato, Eietsu Hasegawa

Journal:

Tetrahedron Letters

Year:

1992

Language:

english

File:

PDF, 257 KB

english, 1992

32

Free radical trapping of α-keto radicals derived from α,β-epoxy ketones via photoinduced single electron transfer process

Eietsu Hasegawa, Kenyuki Ishiyama, Takaaki Horaguchi, Takahachi Shimizu

Journal:

Tetrahedron Letters

Year:

1991

Language:

english

File:

PDF, 240 KB

english, 1991

33

Selective Cα-O bond cleavage of chalcone epoxides induced by pyrylium salt sensitized photoreactions and dark reactions with cerium(iv) salts

Eietsu Hasegawa, Kenyuki Ishiyama, Hiroki Kashiwazaki, Takaaki Horaguchi, Takahachi Shimizu

Journal:

Tetrahedron Letters

Year:

1990

Language:

english

File:

PDF, 248 KB

english, 1990

34

Samarium diiodide-promoted intramolecular ketone–ester coupling reaction: novel cyclization and ring expansion pathway

Kazuki Iwaya, Momoe Nakamura, Eietsu Hasegawa

Journal:

Tetrahedron Letters

Year:

2002

Language:

english

File:

PDF, 76 KB

english, 2002

35

In situ generated tris(p-bromophenyl)amine radical cation promoted electron transfer reaction of cyclopropyl silyl ethers

Eietsu Hasegawa, Koji Kakinuma, Tomoyo Yanaki, Shota Komata

Journal:

Year:

2009

Language:

english

File:

PDF, 281 KB

english, 2009

36

Reductive transformation of α,β-epoxy ketones and other compounds promoted through photoinduced electron transfer processes with 1,3-dimethyl-2-phenylbenzimidazoline (DMPBI)

Eietsu Hasegawa, Akira Yoneoka, Kumiko Suzuki, Teru Kato, Takashi Kitazume, Kazuhiro Yanagi

Journal:

Year:

1999

Language:

english

File:

PDF, 596 KB

english, 1999

37

Reaction of ethyl 2-haloethyl-1-tetralone-2-carboxylate and samarium diiodide: first example of intramolecular O-alkylation of samarium ketyl radical by carbon–halogen bond

Eietsu Hasegawa, Kazuki Iwaya, Takumi Iriyama, Takashi Kitazume, Masaaki Tomura, Yoshiro Yamashita

Journal:

Tetrahedron Letters

Year:

2000

Language:

english

File:

PDF, 147 KB

english, 2000

38

Novel photoreaction of 4-tribromomethyl-4-methyl-2,5-cyclohexadienone with amine

Eietsu Hasegawa, Yukinobu Tamura, Takaaki Horaguchi, Koji Isogai, Toshio Suzuki

Journal:

Tetrahedron Letters

Year:

1994

Language:

english

File:

PDF, 291 KB

english, 1994

39

Photoinduced single electron transfer reactions of 1,3-dithianes and 1,3-dithiolanes sensitized by triphenylpyrylium salt in the presence of molecular oxygen

Masaki Kamata, Yoshihiro Kato, Eietsu Hasegawa

Journal:

Tetrahedron Letters

Year:

1991

Language:

english

File:

PDF, 266 KB

english, 1991

40

First example of samarium diiodide-promoted sequential cyclization and ring-expansion reactions of α-bromomethyl cyclic β-keto esters to homologated γ-keto esters

Eietsu Hasegawa, Takashi Kitazume, Kimiko Suzuki, Emi Tosaka

Journal:

Tetrahedron Letters

Year:

1998

Language:

english

File:

PDF, 239 KB

english, 1998

41

Asymmetric α-2-tosylethenylation of N,N-dialkyl-l-amino acid esters via the formation of non-racemic ammonium enolates

Tayama, Eiji, Igarashi, Tomohito, Iwamoto, Hajime, Hasegawa, Eietsu

Journal:

Organic & Biomolecular Chemistry

Year:

2011

Language:

english

File:

PDF, 250 KB

english, 2011

42

ChemInform Abstract: Asymmetric α-2-Tosylethenylation of N,N-Dialkyl-L-amino Acid Esters via the Formation of Non-Racemic Ammonium Enolates.

Eiji Tayama, Tomohito Igarashi, Hajime Iwamoto, Eietsu Hasegawa

Journal:

Year:

2012

File:

PDF, 36 KB

2012

43

ChemInform Abstract: 1,2-Dimethoxy-4,5-dimethylene: A New Protecting Group for Acyclic Amino Acid Derivatives Prepared by Stevens Rearrangement.

Eiji Tayama, Keisuke Takedachi, Hajime Iwamoto, Eietsu Hasegawa

Journal:

Year:

2012

File:

PDF, 61 KB

2012

44

Furan derivatives. Part 10. Synthesis of cyclohepta[cd]benzofuran

Takaaki Horaguchi, Eietsu Hasegawa, Takahachi Shimizu, Kiyoshi Tanemura, Tsuneo Suzuki

Journal:

Journal of Heterocyclic Chemistry

Year:

1989

File:

PDF, 462 KB

1989

45

Furan derivatives. Part 12 . Synthesis of 2,5-dioxacyclohepta[jkl]-as-indacenes

Takaaki Horaguchi, Kazuhiro Miyazawa, Eietsu Hasegawa, Takahachi Shimizu, Tsuneo Suzuki, Kiyoshi Tanemura

Journal:

Journal of Heterocyclic Chemistry

Year:

1990

File:

PDF, 578 KB

1990

46

Furan derivatives. part 11 [1]. on substituent effects in the synthesis of 3,4,5,6-tetrahydrocyclohepta[cd]benzofurans

Takaaki Horaguchi, Hiroto Kobayashi, Kazuhiro Miyazawa, Eietsu Hasegawa, Takahachi Shimizu, Tsuneo Suzuki, Kiyoshi Tanemura

Journal:

Journal of Heterocyclic Chemistry

Year:

1990

File:

PDF, 478 KB

1990

47

Photocyclization reactions. Part 1. Synthesis of dihydrobenzofuranols using photocyclization of 2-alkoxybenzaldehydes, 2′-alkoxyacetophenones, 2-formylphenoxyacetic acids and 2-acetylphenoxyacetic acids

Takaaki Horaguchi, Chikara Tsukada, Eietsu Hasegawa, Takahachi Shimizu, Tsuneo Suzuki, Kiyoshi Tanemura

Journal:

Journal of Heterocyclic Chemistry

Year:

1991

File:

PDF, 846 KB

1991

48

Furan derivatives. Part 13. Synthesis of thiopyrano[4,3,2-cd]benzofuran

Takaaki Horaguchi, Kohei Hasegawa, Eietsu Hasegawa, Takahachi Shimizu, Kiyoshi Tanemura, Tsuneo Suzuki

Journal:

Journal of Heterocyclic Chemistry

Year:

1992

File:

PDF, 547 KB

1992

49

Photocyclization reactions. Part 4 . Synthesis of naphtho[1,8-bc]-furans and cyclohepta[cd]benzofurans using photocyclization of Ethyl 2-(8-Oxo-5,6,7,8-tetrahydro-1-naphthyloxy)acetates and ethyl 2-(5-Oxo-6,7,8,9-tetrahydro-5H-benzocyclohepten-4-yloxy)acetates

Essam Mohamed Sharshira, Haruki Iwanami, Mutsuo Okamura, Eietsu Hasegawa, Takaaki Horaguchi

Journal:

Journal of Heterocyclic Chemistry

Year:

1996

File:

PDF, 680 KB

1996

50

Photocyclization reactions. Part 3. Synthesis of naphtho[1,8-bc]-furans and Cyclohepta[cd]benzofurans using photocyclization of 8-alkoxy-1,2,3,4-tetrahydro-1-naphthalenones and 4-alkoxy-6,7,8,9-tetrahydro-5H-benzocyclohepten-5-ones

Essam Mohamed Sharshira, Haruki Iwanami, Mutsuo Okamura, Eietsu Hasegawa, Takaaki Horaguchi

Journal:

Journal of Heterocyclic Chemistry

Year:

1996

File:

PDF, 678 KB

1996