- Chromoselective Synthesis of Sulfonyl Chlorides and Sulfonamides with Potassium Poly(heptazine imide) Photocatalyst
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Among external stimuli used to promote a chemical reaction, photocatalysis possesses a unique one—light. Photons are traceless reagents that provide an exclusive opportunity to alter chemoselectivity of the photocatalytic reaction varying the color of incident light. This strategy may be implemented by using a sensitizer capable to activate a specific reaction pathway depending on the excitation light. Herein, we use potassium poly(heptazine imide) (K-PHI), a type of carbon nitride, to generate selectively three different products from S-arylthioacetates simply varying the excitation light and otherwise identical conditions. Namely, arylchlorides are produced under UV/purple, sulfonyl chlorides with blue/white, and diaryldisulfides at green to red light. A combination of the negatively charged polyanion, highly positive potential of the valence band, presence of intraband states, ability to sensitize singlet oxygen, and multi-electron transfer is shown to enable this chromoselective conversion of thioacetates.
- Antonietti, Markus,Guldi, Dirk M.,Markushyna, Yevheniia,Savateev, Aleksandr,Schü?lbauer, Christoph M.,Ullrich, Tobias
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supporting information
p. 20543 - 20550
(2021/08/12)
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- Aromatic Chlorosulfonylation by Photoredox Catalysis
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Visible-light photoredox catalysis enables the efficient synthesis of arenesulfonyl chlorides from anilines. The new protocol involves the convenient in situ preparation of arenediazonium salts (from anilines) and the reactive gases SO2and HCl (from aqueous SOCl2). The photocatalytic chlorosulfonylation operates at mild conditions (room temperature, acetonitrile/water) with low catalyst loading. Various functional groups are tolerated (e.g., halides, azides, nitro groups, CF3, SF5, esters, heteroarenes). Theoretical and experimental studies support a photoredox-catalysis mechanism.
- Májek, Michal,Neumeier, Michael,Jacobi von Wangelin, Axel
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p. 151 - 155
(2017/01/17)
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- A simple and highly effective oxidative chlorination protocol for the preparation of arenesulfonyl chlorides
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2,4-Dichloro-5,5-dimethylhydantoin (DCDMH) was found to be a mild and efficient reagent for the direct oxidative conversion of sulfur compounds to the corresponding arenesulfonyl chlorides in good to excellent yields through oxidative chlorination. The method is suitable for many types of sulfur substrates (thiols, disulfides, and benzylic sulfides). The overall process is simple, practical, and it provides convenient access to a variety of aryl or heteroarylsulfonyl chlorides. The mild reaction conditions and the broad substrate scope render this method attractive and complementary to existing syntheses of aryl or heteroarylsulfonyl chlorides.
- Pu, Yu-Ming,Christesen, Alan,Ku, Yi-Yin
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supporting information; experimental part
p. 418 - 421
(2010/03/04)
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- Phenylenediamine urotensin-II receptor antagonists and CCR-9 antagonists
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The present invention relates to urotensin II receptor antagonists, CCR-9 antagonists, pharmaceutical compositions containing them and their use.
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