- Direct and indirect electrochemical generation of alkoxycarbenium ion pools from thioacetals
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Thioacetals were found to be effective precursors to generate and accumulate alkoxycarbenium ions based on direct and indirect cation pool methods. Alkoxycarbenium ions thus generated reacted with carbon nucleophiles such as allylsilanes and enol silyl et
- Matsumoto, Kouichi,Ueoka, Koji,Suzuki, Shinkiti,Suga, Seiji,Yoshida, Jun-ichi
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experimental part
p. 10901 - 10907
(2010/02/27)
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- Indirect cation pool method. Rapid generation of alkoxycarbenium ion pools from thioacetals
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A sequential one-pot indirect cation pool method has been developed. The method involves the electrochemical generation and accumulation of ArS(ArSSAr)+ at low temperature (step 1) and the follow-up reaction with a thioacetal to generate an alk
- Suga, Seiji,Matsumoto, Kouichi,Ueoka, Koji,Yoshida, Jun-Ichi
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p. 7710 - 7711
(2007/10/03)
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- Lithium bromide, a novel and highly effective catalyst for monothioacetalization of acetals under mild reaction conditions
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Lithium bromide is efficient as a catalyst for the monothioacetalization of acetals under mild reaction conditions to provide products in excellent yields with high chemoselectivity.
- Ono,Negoro,Sato
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p. 1581 - 1583
(2007/10/03)
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- Polymer-supported dicyanoketene acetal as a π-acid catalyst: Monothioacetalization and carbon-carbon bond formation of acetals
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Polymeric dicyanoketene acetals (DCKA) were synthesized by copolymerization of styrene and divinylbenzene or ethylene glycol dimethacrylate. These novel polymers could be used successfully as recyclable π-acid catalysts in monothioaCetalization or carbon-carbon bond forming reaction of acetals.
- Tanaka, Nobuyuki,Miura, Tsuyoshi,Masaki, Yukio
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p. 1010 - 1016
(2007/10/03)
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- Unprecedented polymer-supported π-acid: Synthesis and its application as a promoter to the monothioacetalization of acetals
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A novel polymer was synthesized by copolymerization of styrene monomer bearing dicyanoketene acetal functionality and ethylene glycol dimethacrylate, and used successfully as a recyclable π-acid catalyst in monothioacetalization of aromatic, aliphatic, acyclic, and cyclic acetals with thiophenol and phenylthiotrimethylsilane.
- Masaki, Yukio,Tanaka, Nobuyuki,Miura, Tsuyoshi
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p. 5799 - 5802
(2007/10/03)
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- Monothioacetalization of acetals catalyzed by dicyanoketene acetals
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A type of capto-dative olefin, dicyanoketene acetal such as dicyanoketene dimethyl acetal and ethylene acetal is introduced to be a novel type of π-acid catalyst for the monothioacetalization of acetals as well as the corresponding α,β-unsaturated systems. Particularly, the catalytic activity of dicyanoketene ethylene acetal was found to be superior to that of tetracyanoethylene and highly chemoselective in the crossover reaction of a ketone-, aldehyde-acetal, an alcohol THP-, and MOM-ether providing a ketone monothioacetal favorably.
- Miura, Tsuyoshi,Masaki, Yukio
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p. 10477 - 10486
(2007/10/02)
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- Dicyanoketene Acetals, a Novel Type of ?-Acid Catalyst for Monothioacetalization of Acetals
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Dicyanoketene acetals such as dicyanoketene dimethyl acetal and ethylene acetal are introduced to be a novel type of ?-acid catalyst for the monothioacetalization of acetals.Particularly, the catalytic activity of dicyanoketene ethylene acetal was found to be superior to that of tetracyanoethylene and chemoselective in the crossover reaction of the monothioacetalization of a ketone-, an aldehyde-acetal and an alcohol THP-ether providing a ketone monothioacetal favorably.
- Miura, Tsuyoshi,Masaki, Yukio
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p. 7961 - 7964
(2007/10/02)
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- ACTIVATION AND SYNTHETIC APPLICATIONS OF THIOSTANNANES. THIOALKOXYLATION OF ACETALS
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The Sn-S bonds in thiostannanes, BunSn(SPh)4-n, are activated towards acetals in the presence of BF3*OEt2.Acetals of various aldehydes and ketones are converted into the corresponding monothioacetals under mild conditions.Employment of α-enal acetals induces Michael addition to give synthetically useful γ-alkoxyally sulfides.
- Sato, Tsuneo,Otera, Junzo,Nozaki, Hitosi
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p. 1209 - 1218
(2007/10/02)
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- Organotin-Mediated Preparation of Monothioacetals
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Monothioacetals are obtained by treating the corresponding acetals with organotin thiophenoxides in the presence of BF3*OEt2.The reaction proceeds under mild conditions to provide the desired compounds with high selectivity.
- Sato, Tsuneo,Kobayashi, Takamitsu,Gojo, Tamehisa,Yoshida, Enji,Otera, Junzo,Nozaki, Hitosi
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p. 1661 - 1664
(2007/10/02)
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- METHOXY(PHENYLTHIO)METHANE AS AN AMBI-EQUVIVALENT OF A METHOXY- OR PHENYLTHIOMETHYLENE 1,1-DIPOLE
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Methoxy(phenylthio)methane undergoes electrophilic alkylation followed by nucleophilic allylation or propargylation which is dramatically changed depending on the Lewis acid employed providing a methoxy- or phenylthiomethylene 1,1-dipole synthon.
- Sato, Tsuneo,Okura, Shuji,Otera, Junzo,Nozaki, Hitosi
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p. 6299 - 6302
(2007/10/02)
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