- Redox-active alkylsulfones as precursors for alkyl radicals under photoredox catalysis
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A method for generating alkyl radicals using visible-light photoredox catalysis is described. This procedure was found to present an efficient means to access a diverse collection of 1°, 2°, and 3° alkyl radicals through the single-electron transfer of sulfones under mild reaction conditions. These alkyl radicals generated via the reductive desulfonylation of readily synthesized and stable alkylsulfones were engaged to forge C-C bonds. A detailed study was also carried out to shed light on the mechanism.
- Patel, Sandeep,Paul, Biprajit,Paul, Hrishikesh,Shankhdhar, Rajat,Chatterjee, Indranil
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p. 4857 - 4860
(2022/04/19)
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- Conformational Analysis of Acyclic α-Fluoro Sulfur Motifs
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Bioactive small molecules containing α-fluoro sulfur motifs [RS(O)nCH2F] are appearing with increasing frequency in the pharmaceutical and agrochemical sectors. Prominent examples include the anti-asthma drug Flovent and t
- Erdeljac, Nathalie,Mück-Lichtenfeld, Christian,Daniliuc, Constantin G.,Gilmour, Ryan
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p. 13704 - 13715
(2020/10/02)
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- One-pot sequential synthesis and antifungal activity of 2-(benzylsulfonyl)benzothiazole derivatives
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New antifungal agrochemicals, derived from 2-(benzylsulfonyl)benzothiazole were synthesized by an environmentally friendly method, using water as reaction medium. These compounds were prepared by a one-pot, two-step synthesis, starting from 2-mercaptobenzothiazole and benzyl halides. The potential fungicides were tested against a panel of phytopathogenic fungi, with many of them showing a significant improvement compared to the non-oxidized analogues and the commercial antifungal Captan. The new derivatives 2-((2-chlorobenzyl)sulfonyl)benzo[d]thiazole (4f) and 2-((4-methylbenzyl)sulfonyl)benzo[d]thiazole (4k) presented remarkable properties, being able to inhibit the growth of two resistant moulds (Aspergillus fumigatus and Aspergillus ustus). Both 4f and 4k could be classified as broad-spectrum fungicides, emerging as possible candidates for the control of these moulds, which have negative impact in food production.
- Ballari, María Sol,Herrera Cano, Natividad,Wunderlin, Daniel A.,Feresin, Gabriela E.,Santiago, Ana N.
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p. 29405 - 29413
(2019/09/30)
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- One and Two-Carbon Homologation of Primary and Secondary Alcohols to Corresponding Carboxylic Esters Using β-Carbonyl BT Sulfones as a Common Intermediate
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Herein we report the efficient one- and two-carbon homologation of 1° and 2° alcohols to their corresponding homologated esters via the Mitsunobu reaction using β-carbonyl benzothiazole (BT) sulfone intermediates. The one-carbon homologation approach uses standard Mitsunobu C-S bond formation, oxidation and subsequent alkylation, while the two-carbon homologation uses a less common C-C bond forming Mitsunobu reaction. In this latter case, the use of β-BT sulfone bearing esters lowers the pKa sufficiently enough for the substrate to be used as a carbon-based nucleophile and deliver the homologated β-BT sulfone ester, and this superfluous sulfone group can then be cleaved. In this paper we describe several methods for the effective desulfonylation of BT sulfones and have developed methodology for one-pot alkylation-desulfonylation sequences. As such, overall, a one-carbon homologation sequence can be achieved in a two-pot (four step) procedure and the two-carbon homologation in a two-pot (three step) procedure (three-pot; four step when C-acid synthesis is included). This methodology has been applied to a wide variety of functionality (esters, silyl ethers, benzyls, heteroaryls, ketones, olefins and alkynes) and are all tolerated well providing good to very good overall yields. The power of our method was demonstrated in site-selective ingenol C20 allylic alcohol two-carbon homologation.
- Bon, David J.-Y. D.,Ková?, Ond?ej,Ferugová, Vendula,Zále?ák, Franti?ek,Pospí?il, Ji?í
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p. 4990 - 5001
(2018/05/17)
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- Benzothiazole Sulfinate: A Sulfinic Acid Transfer Reagent under Oxidation-Free Conditions
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Sulfinic acids are commonly encountered intermediates found in natural product synthesis and medicinal chemistry. However, because of high reactivity, instability, and harsh reaction conditions, they are difficult to synthesize. Herein we have developed an oxidation-free method to produce sulfinic acids and sulfinate salts using 2-sulfinyl benzothiazole (BTS). We have also demonstrated the synthetic usefulness by developing one-pot syntheses of sulfones and sulfonamides.
- Day, Jacob J.,Neill, Deshka L.,Xu, Shi,Xian, Ming
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supporting information
p. 3819 - 3822
(2017/07/26)
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- Practical synthesis of β-oxo benzo[d]thiazolyl sulfones: Scope and limitations
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In this paper, we discuss our new synthetic approach towards functionalized benzo[d]thiazolyl (BT) sulfones, based on the reunion of alkyl BT sulfones and various electrophiles (e.g. R-CO-X, RO-CO-X, RS-CO-X, Ts-X...). All important aspects of this coupling reaction, including relevant and undesirable side reactions, are evaluated by means of calculations and competitive experiments. The scope and limitations of this method are established. The Royal Society of Chemistry 2012.
- Pospiil, Jii,Robiette, Raphael,Sato, Hitoshi,Debrus, Kevin
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supporting information; experimental part
p. 1225 - 1234
(2012/03/07)
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- Practical synthesis of β-acyl and β-alkoxycarbonyl heterocyclic sulfones
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A short and efficient synthesis for β-acyl and β-alkoxycarbonyl heterocyclic sulfones containing benzothiazol (BT) and phenyltetrazol (PT) heterocyclic core is presented here. The method seems to be general and provides the desired C-nucleophiles in very good to excellent yields from readily available starting materials.
- Pospisil, Jiri,Sato, Hitoshi
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p. 2269 - 2272
(2011/06/11)
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- Chemoselective sulfoxidation by H2O2 or HNO3 using a phosphate impregnated titania catalyst
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A variety of organosulfur compounds have been selectively oxidized to the corresponding sulfoxides by either H2O2 or HNO3 using a newly developed solid acid catalyst composed of 84.5% of TiO2 and 15.5% of [Ti4H11(PO4)9]·nH2O (n = 1-4). The chemoselective oxidation of sulfides in the presence of vulnerable groups such as -CN, -C{double bond, long}C-, -CHO, or -OH, as well as sulfoxidation of substrates like benzothiazole, glycosyl sulfide, and dibenzothiophenes is some of the important attribute of the protocol. Nitric acid, under the present experimental conditions, brings about relatively better selectivity than hydrogen peroxide.
- Bharadwaj, Saitanya K.,Sharma, Susanda N.,Hussain, Sahid,Chaudhuri, Mihir K.
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experimental part
p. 3767 - 3771
(2009/10/11)
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- Fast and efficient oxidation of sulfides to sulfones with N,N′-dibenzyl-N,N,N′,N′-tetramethyl diammonium permanganate
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Selective oxidation of sulfides to sulfones was developed using N,N′-dibenzyl-N,N,N′,N′-tetramethylethylene diammonium permanganate. A variety of aromatic and aliphatic sulfides were oxidized to the corresponding sulfones immediately in excellent yields at r.t. Copyright Taylor & Francis Group, LLC.
- Lakouraj,Tajbakhsh,Tashakkorian,Ghodrati
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p. 485 - 490
(2007/10/03)
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- THIOREDOXIN AND THIOREDOXIN REDUCTASE INHIBITORS
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The present invention relates to sulfone derivatives and to their use as modulators of the thioredoxin/thioredoxin reductase redox system, including for the treatment and/or prevention of pathophysiological conditions mediated by thioredoxin/thioredoxin reductase, such as cancer, HIV/ AIDS, Alzheimer's disease, rheumatoid arthritis, and skin disorders. Also provided are pharmaceutical compositions comprising the inventive sulfones.
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Page/Page column 58; 13/22; 14/22
(2008/06/13)
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- High-yield synthesis of fluorinated benzothiazolyl sulfones: General synthons for fluoro-Julia olefinations
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General, high-yield tandem electrophilic fluorination and modified Julia olefination for the synthesis of fluoro olefins is reported. A series of α-fluoro 1,3-benzothiazol-2-yl sulfone-based synthons were synthesized via deprotonation-fluorination. Of critical importance for high-yield fluorinations were heterogeneous reaction conditions, as under homogeneous conditions only starting sulfones were recovered. The α-fluoro 1,3-benzothiazol-2-yl sulfones so obtained were subjected to condensations with a variety of aldehydes and ketones to afford high yields of regiospecifically fluorinated olefins.
- Ghosh, Arun K.,Zajc, Barbara
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p. 1553 - 1556
(2007/10/03)
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- Stereochemistry of direct olefin formation from carbonyl compounds and lithiated heterocyclic sulfones
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The conditions for the title reaction were studied for the 2-benzothiazole and 2-pyridine series and for some examples in the 2-pyrimidine series.The olefin preparations were generally observed to be more efficient for 2-BT-sulfone systems.From the data of the hundred cases studied, it can be concluded that (E)-olefins are obtained: (i) from saturated BT-sulfones and aromatic aldehydes; and (ii) from benzylic BT-sulfones and branched saturated aldehydes (isobutyraldehyde, pivalaldehyde) or α,β-ethylenic or aromatic aldehydes. (Z)-olefins arise: (i) fom propargylic BT-sulfones and saturated or aromatic aldehydes; and (ii) from allylic or benzylic Pyr-sulfones and saturated aldehydes.Possible mechanisms for this new olefination procedure were examined. - heteroaromatic sulfones, organolithium derivatives, intramolecular ipso reactions, stereochemistry, elimination, olefination.
- Baudin, J. B.,Hareau, G.,Julia, S. A.,Lorne, R.,Ruel, O.
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p. 856 - 878
(2007/10/02)
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- Stereochemistry of the olefin formation from anti and syn heterocyclic β-hydroxy sulfones.
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Reaction of aldehydes R2-CHO with the new lithio derivatives of 2-benzothiazoles or pyridines R1-CH2-SO2-Het afforded the corresponding β-hydroxy sulfones which are stable in the pyridine series and generally unstable in the benzothiazole series except for anti derivatives 10a and 20c. t-Butyl-dimethyl silyl ethers of all the heterocyclic β-hydroxy sulfones have been obtained by oxidation of the corresponding anti and syn sulfides, which have been stereoselectively prepared from the epoxides 17, 19, 21 and 23.The lithium or tetrabutylammonium alkoxides of heterocyclic β-hydroxy sulfones undergo an intramolecular addition to the neighboring C=N group followed by an S to O benzothiazole (or pyridine) transfer, and simultaneous extrusion of sulfur dioxide, ejection of benzothiazol-2(3H)-one anion and formation of the corresponding olefins.From the data of twenty cases studied, it can be concluded that the final elimination is entirely antiperiplanar only for the alkoxides of β-hydroxy-BT- or Pyr-sulfones anti or syn bearing saturated aliphatic chains R1 and R2 and for anti derivatives with R1 = R2 = C6H5.Due to their equilibration however, the alkoxides of numerous derivatives of heterocyclic (3-methylbut-2-enyl) or (phenylmethyl) sulfones do not follow entirely the above antiperiplanar elimination. Keywords: heteroaromatic sulfones / intramolecular ipso reaction / organolithium derivatives / stereochemistry / eliminations / olefination
- Baudin, J. B.,Hareau, G.,Julia, S. A.,Ruel, O.
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p. 336 - 357
(2007/10/02)
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- A direct synthesis of olefins by reaction of carbonyl compounds with lithio derivatives of 2-[alkyl- or (2'-alkenyl)- or benzyl-sulfonyl]-benzothiazoles
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During the title reaction, the lithium alkoxides formed as intermediates undergo an intramolecular addition to the neighboring C = N group followed an S to O benzothiazole transfer and simultaneous extrusion of sulfur dioxide and ejection of 2(3H)-benzothiazolone anion.
- Baudin,Hareau,Julia,Ruel
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p. 1175 - 1178
(2007/10/02)
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- A CONVENIENT AND GENERAL SYNTHESIS OF ALKANE SULFINIC ACIDS
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2-(Alkylsulfonyl)benzothiazoles are reduced with sodium tetrahydroborate to give alkane sulfinic acids in good yield.
- Ueno, Yoshio,Kojima, Akihiko,Okawara, Makoto
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p. 2125 - 2128
(2007/10/02)
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