- Dithioacetalization or thioetherification of benzyl alcohols using 9-mesityl-10-methylacridinium perchlorate photocatalyst
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We report herein the use of 9-mesityl-10-methylacridinium perchlorate as the visible-light photocatalyst for dithioacetalization or thioetherification of benzyl alcohols in one pot using aerial dioxygen as a terminal oxidant. EPR analysis and Stern-Volmer
- Pramanik, Milan,Choudhuri, Khokan,Mathuri, Ashis,Mal, Prasenjit
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supporting information
p. 10211 - 10214
(2020/09/21)
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- Sequential one-pot addition of excess aryl-grignard reagents and electrophiles to O-alkyl thioformates
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The sequential addition of aromatic Grignard reagents to O-alkyl thioformates proceeded to completion within 30s to give aryl benzylic sulfanes in good yields. This reaction may begin with the nucleophilic attack of the Grignard reagent onto the carbon atom of the O-alkyl thioformates, followed by the elimination of ROMgBr to generate aromatic thioaldehydes, which then react with a second molecule of the Grignard reagent at the sulfur atom to form arylsulfanyl benzylic Grignard reagents. To confirm the generation of aromatic thioaldehydes, the reaction between O-alkyl thioformates and phenyl Grignard reagent was carried out in the presence of cyclopentadiene. As a result, hetero-Diels-Alder adducts of the thioaldehyde and the diene were formed. The treatment of a mixture of the thioformate and phenyl Grignard reagent with iodine gave 1,2-bis(phenylsulfanyl)-1,2-diphenyl ethane as a product, which indicated the formation of arylsulfanyl benzylic Grignard reagents in the reaction mixture. When electrophiles were added to the Grignard reagents that were generated insitu, four-component coupling products, that is, O-alkyl thioformates, two molecules of Grignard reagents, and electrophiles, were obtained in moderate-to-good yields. The use of silyl chloride or allylic bromides gave the adducts within 5min, whereas the reaction with benzylic halides required more than 30min. The addition to carbonyl compounds was complete within 1min and the use of lithium bromide as an additive enhanced the yields of the four-component coupling products. Finally, oxiranes and imines also participated in the coupling reaction. Into the melting pot: The addition of excess aryl Grignard reagents and electrophiles to O-alkyl thioformates gives aryl sulfanes through four-component coupling reactions (see scheme). These reactions may involve the formation of aromatic thioaldehydes and aryl-benzylic Grignard reagents as intermediates. For addition to carbonyl compounds, the use of lithium halides as an additive enhanced the efficiency of the reaction. Copyright
- Murai, Toshiaki,Morikawa, Kenta,Maruyama, Toshifumi
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p. 13112 - 13119
(2013/10/01)
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- An efficient, mild and intermolecular ullmann-type synthesis of thioethers catalyzed by a diol-copper(I) complex
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A wide range of diaryl sulfides and aryl alkyl sulfides are synthesized under mild reaction conditions from the corresponding aryl iodides and aromatic/aliphatic thiols through Ullmann-type intermolecular coupling reactions in the presence of catalytic amount of easily available novel trans-9,10-dihydro-9,10-ethanoanthracene-11,12-dimethanol-copper(I) bromide complex at 82 C. The catalytic system is not only capable of coupling electron-withdrawing and electron-releasing substituent-containing substrates, but also tolerates a broad range of functional groups including heteroatom-containing aryl iodides and thiols.
- Prasad,Sekar, Govindasamy
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experimental part
p. 79 - 84
(2010/06/15)
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- ESTROGEN RECEPTOR LIGANDS
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The invention described herein discloses bisphenol alkane compounds of formulae III and Vl and similar compounds as well as 4-[4-hydroxybenzylthio]- phenol compounds which are estrogen receptor ligands, composition containing these compounds and methods for treating various conditions using the compounds and compositions of this invention.
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Page/Page column 31-32
(2010/04/06)
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- An efficient intermolecular C(aryl)-S bond forming reaction catalyzed by BINAM-copper(II) complex
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A wide range of diaryl thioethers and aryl alkyl thioethers are synthesized from the corresponding aryl iodides and aromatic/aliphatic thiols through Ullmann type intermolecular coupling reactions in the presence of a catalytic amount of easily available BINAM-Cu(OTf)2 complex. Less reactive aryl bromides have also been shown to react with thiols under identical reaction conditions to give good yields of the thioethers without increasing the reaction temperature and time.
- Prasad,Naidu, Ajay B.,Sekar
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experimental part
p. 1411 - 1415
(2009/06/18)
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- Synthesis of aryl benzyl NH-sulfoximines
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Efficient synthesis and characterisation of a series of aryl benzyl NH-sulfoximines are described. While N-protected versions of aryl benzyl sulfoximines have been previously described, reports of their deprotection are very limited, presumably due to lab
- Barry, Nicola,Brondel, Nicolas,Lawrence, Simon E.,Maguire, Anita R.
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experimental part
p. 10660 - 10670
(2010/01/16)
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- CsF-Celite, an efficient solid state reagent for the syntheses of thioesters and thioethers
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Coupling reactions of a number of aliphatic, aromatic, and heterocyclic compounds bearing an acidic hydrogen atom attached to sulfur, with alkyl, acyl, benzyl, or benzoyl halides in acetonitrile with cesium fluoride-Celite are described. This procedure is convenient, efficient, and practical for the preparation of thioethers and thioesters. Springer-Verlag 2005.
- Shah, Syed T. A.,Khan, Khalid M.,Hussain, Hidayat,Hayat, Safdar,Voelter, Wolfgang
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p. 1583 - 1589
(2007/10/03)
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- An alternative approach towards the syntheses of thioethers and thioesters using CsF-Celite in acetonitrile
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It has been found that syntheses of thioethers and thioesters of aliphatic, aromatic and heterocyclic compounds, bearing thiol groups, can be accomplished with alkyl, acyl, benzyl or benzoyl halides in acetonitrile and cesium fluoride-Celite. In this manner, compounds like ethanethiol, 1-pentanethiol, thiophenol, 4-methoxythiophenol, 4-nitrothiophenol, and 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, and 2-mercapto-2-thiazoline can be successfully alkylated, acylated, benzylated or benzoylated. This procedure is convenient, efficient and practical for the preparation of thioethers and thioesters.
- Shah, Syed Tasadaque Ali,Khan, Khalid Mohammed,Martinez Heinrich, Angelica,Voelter, Wolfgang
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p. 8281 - 8283
(2007/10/03)
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- Direct synthesis of thioethers from sulfonyl chlorides and activated alcohols
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An efficient, safe one-pot synthesis of thioethers from aromatic sulfonyl chlorides and activated alcohols has been developed under non-aqueous conditions.
- Martin, Michael T,Thomas, Alford M,York, Douglas G
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p. 2145 - 2147
(2007/10/03)
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- Isotope effects in nucleophilic substitution reactions. IV. The effect of changing a substituent at the α carbon on the structure os SN2 transition states
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Kinetic studies, secondary α-deuterium kinetic isotope effects, primary chlorine kinetic isotope effects (1), Hammett ρ values determined by changing the substituent in the nucleophile, and activation parameters have been used to determine the detailed (relative) structures of the transition states for the S2 reactions between para-substituted benzyl chlorides and thiophenoxide ion.A rationale for the U-shaped Hammett ρ plots observed when para-substituted benzyl compounds react with negatively charged nucleophiles is also presented.
- Westaway, Kenneth Charles,Waszczylo, Zbigniew
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p. 2500 - 2520
(2007/10/02)
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