- PhIO-Mediated oxidative dethioacetalization/dethioketalization under water-free conditions
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Treatment of thioacetals and thioketals with iodosobenzene in anhydrous DCM conveniently afforded the corresponding carbonyl compounds in high yields under water-free conditions. The mechanistic studies indicate that this dethioacetalization/dethioketalization process does not need water and the oxygen of the carbonyl products comes from the hypervalent iodine reagent.
- Du, Yunfei,Ouyang, Yaxin,Wang, Xi,Wang, Xiaofan,Yu, Zhenyang,Zhao, Bingyue,Zhao, Kang
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- Pot-economy autooxidative condensation of 2-Aryl-2-lithio-1,3-dithianes
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The autoxidative condensation of 2-aryl-2-lithio-1,3-dithianes is here reported. Treatment of 2-aryl-1,3-dithianes with n-BuLi in the absence of any electrophile leads to condensation of three molecules of 1,3-dithianes and formation of highly functionalized α-thioether ketones orthothioesters in 51-89% yields upon air exposure. The method was further expanded to benzaldehyde dithioacetals, affording corresponding orthothioesters and α-thioether ketones in 48-97% yields. The experimental results combined with density functional theory studies support a mechanism triggered by the autoxidation of 2-aryl-2-lithio-1,3-dithianes to yield a highly reactive thioester that undergoes condensation with two other molecules of 2-aryl-2-lithio-1,3-dithiane.
- Vale, Joao R.,Rimpil?inen, Tatu,Siev?nen, Elina,Rissanen, Kari,Afonso, Carlos A. M.,Candeias, Nuno R.
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p. 1948 - 1958
(2018/02/23)
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- Mesoporous sBa-15 silica catalyst functionalized with phenylsulfonic acid groups (SbA-15-ph-So3h) as efficient nanocatalyst for chemoselective thioacetalization of carbonyl compounds
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In this research a Nano acidic catalyst was prepared and its efficiency on thioacetalization of carbonyl compounds was examined. For this aim we used modified SBA-15 as support, which have been modified by phenolic and sulfonic acid. SBA-15 is a member of
- Sedrpoushan, Alireza,Ghazizadeh, Habibollah
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p. 112 - 118
(2017/01/18)
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- Silica phenyl sulfonic acid as a solid acid heterogeneous catalyst for chemoselective thioacetalization of carbonyl compounds and dethioacetalization under mild conditions
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Silica phenyl sulfonic acid (SPSA) is an effective catalyst for chemoselective thioacetalization of aldehydes in the presence of ketones under neutral conditions. In addition, a simple and an efficient procedure for deprotection of 1,3-dithianes and 1,3-dithiolanes of aromatic, aliphatic, and α,β-unsaturated aldehydes and ketones in the solvent-free to the corresponding parent carbonyl compounds was successfully carried out with SPSA in excellent yields.
- Veisi, Hojat,Sedrpoushan, Alireza,Zolfigol, Mohammad Ali,Mohanazadeh, Farajollah,Hemmati, Saba
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p. E204-E206
(2013/06/04)
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- Silica-supported phosphorus pentoxide: A reusable catalyst for S,S-acetalization of carbonyl groups under ambient conditions
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Phosphorus pentoxide supported on silica gel (P2O 5/SiO2) efficiently acts as a highly active and reusable catalyst for cyclic and non-cyclic S,S-acetalization of a variety of carbonyl compounds under mild, solvent-free an
- Shaterian, Hamid Reza,Azizi, Kobra,Fahimi, Nafiseh
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experimental part
p. 85 - 91
(2012/01/06)
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- 1,3-dibromo-5,5-dimethylhydantoin (DBH) as a mild and efficient catalyst for chemoselective thioacetalization of carbonyl compounds and dethioacetalization under mild conditions
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Hydantoin bromide is an effective catalyst for chemoselective thioacetalization of aldehydes in the presence of ketones under neutral conditions. In addition, a simple and efficient procedure for the deprotection of 1,3-dithianes and 1,3-dithiolanes of ar
- Veisi, Hojat,Amiri, Mostafa,Hamidian, Amir Hossein,Malakootikhah, Javad,Fatolahi, Leila,Faraji, Alireza,Sedrpoushan, Alireza,Maleki, Behrooz,Saremi, Shokufe Ghahri,Noroozi, Mohammad,Bahadoori, Fatemeh,Veisi, Somayeh
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experimental part
p. 689 - 696
(2010/06/19)
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- Chemoselective (trans)thioacetalization of carbonyl compounds with a reusable lewis acid-surfactant-combined copper bis(dodecyl sulfate) catalyst in water
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A Lewis acid-surfactant-combined copper bis(dodecyl sulfate) [Cu(DS) 2] catalyst served as an efficient and reusable catalyst for the thioacetalization and transthioacetalization of carbonyl compounds and O,O-acetals in water at room temperature. Some of the major advantages of this procedure are high chemoselectivity, ease of operation and purification without any organic solvent, and high yields. Georg Thieme Verlag Stuttgart.
- Weng, Shiue-Shien,Chang, Shen-Chun,Chang, Tsuan-Hao,Chyn, Jong-Pyng,Lee, Shu-Wei,Lin, Chao-An,Chen, Fong-Kuang
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experimental part
p. 1493 - 1499
(2010/10/03)
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- Synthesis of benzo[b]furans by palladium-NHC catalyzed ring closure of o-bromobenzyl ketones
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The palladium-catalyzed ring closure of aryl o-bromobenzyl ketones, easily accessible from aromatic aldehydes and 2- bromobenzyl bromide, provides a straightforward route to 2-aryl- benzofurans. A study of the ring closure revealed that a heterocyclic car
- Farago, Janos,Kotschy, Andras
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scheme or table
p. 85 - 90
(2009/06/18)
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- Catalytic carbon-sulfur bond formation by amphoteric vanadyl triflate: exploring with thia-Michael addition, thioacetalization, and transthioacetalization reactions
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A series of thiols have been examined as protic nucleophiles for Michael-type additions to α,β-unsaturated carbonyls as well as double nucleophilic condensations with aldehydes, ketones, and acetals catalyzed by amphoteric, water-tolerant vanadyl triflate under mild and neutral conditions. The newly developed C-S bond formation protocols were carried out smoothly in good to high yields in a highly chemoselective manner.
- Chen, Chien-Tien,Lin, Yow-Dzer,Liu, Cheng-Yuan
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supporting information; experimental part
p. 10470 - 10476
(2010/02/28)
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- Ferric hydrogensulfate as effective and recyclable catalyst for mild dithioacetalization of aldehydes and ketones
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Ferric hydrogensulfate has been found to be an extremely efficient and recyclable heterogeneous catalyst for dithioacetalization reactions. Carbonyl compounds have been successfully converted into their corresponding dithiolanes and dithianes derivatives
- Shaterian, Hamid Reza,Ahmadian, Hamid Reza,Ghashang, Majid,Doostmohammadi, Razieh,Yarahmadi, Hossein
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experimental part
p. 1099 - 1108
(2009/04/07)
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- Chemoselective dithioacetalization and oxathioacetalization of carbonyl compounds using alumina sulfuric acid as catalyst
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Carbonyl compounds have been successfully converted into their corresponding dithiolane, dithiane, and oxathiolane derivatives using a catalytic amount of alumina sulfuric acid (Al2O3-SO3H) with excellent yields at room temperature in short reaction times under mild conditions. This simple method is a highly chemoselective procedure for protection of aldehydes in the presence of ketones, and the heterogeneous catalyst can be recovered and reused several times without any loss of its activity. Copyright Taylor & Francis Group, LLC.
- Shaterian, Hamid Reza,Hosseinian, Asghar,Ghashang, Majid
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experimental part
p. 4097 - 4106
(2009/04/11)
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- Acid-promoted thioacetalization in water using 2-(1,3-dithian-2-ylidene) malonic acid as an odorless and efficient thioacetalization reagent
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Thioacetalization using 2-(1,3-dithian-2-ylidene)malonic acid 1 as a nonthiolic, odorless 1,3-propanedithiol equivalent promoted by p-dodecylbenzenesulfonic acid in water has been achieved. A range of selected carbonyl compounds 2 was converted into the corresponding dithioacetals 3 in high yields. Moreover, the thioacetalization showed high chemoselectivity between aldehydes and ketones. Copyright Taylor & Francis Group, LLC.
- Ouyang, Yan,Dong, Dewen,Liang, Yongjiu,Chai, Yanyan,Liu, Qun
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p. 993 - 1000
(2007/10/03)
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- Chemoselective thioacetalization using 3-(1,3-dithian-2-ylidene)pentane-2, 4-dione as an odorless and efficient propane-1,3-dithiol equivalent under solvent-free conditions
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As a non-thiolic, odorless propane-1,3-dithiol equivalent, 3-(1,3-dithian-2-ylidene)pentane-2,4-dione has been investigated in acid-promoted thioacetalization under solvent-free conditions. A range of selected aldehydes and aliphatic ketones have been converted into the corresponding dithioacetals in high yields. The relatively slow reaction rate of aromatic ketones allowed chemoselective protection of aromatic aldehydes or aliphatic ketones, in contrast to aromatic ketones. Georg Thieme Verlag Stuttgart.
- Ouyang, Yan,Dong, Dewen,Zheng, Chunbai,Yu, Haifeng,Liu, Qun,Fu, Zhenqian
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p. 3801 - 3804
(2008/02/09)
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- Chemoselective thioacetalization in water: 3-(1,3-dithian-2-ylidene) pentane-2,4-dione as an odorless, efficient, and practical thioacetalization reagent
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A chemoselective thioacetalization utilizing 3-(1,3-dithian-2-ylidene) pentane-2,4-dione as a novel nonthiolic, odorless 1,3-propanedithiol equivalent catalyzed by p-dodecylbenze-nesulfonic acid in water has been developed.
- Dong, Dewen,Ouyang, Yan,Yu, Haifeng,Liu, Qun,Liu, Jun,Wang, Mang,Zhu, Jing
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p. 4535 - 4537
(2007/10/03)
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- Bismuth oxide perchlorate as a highly efficient and chemoselective catalyst for thioacetalization of carbonyl compounds under solvent-free conditions
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Bismuth oxide perchlorate efficiently and chemoselectively catalyzes the thioacetalization of both aliphatic and aromatic carbonyl compounds under solvent-free conditions. Stearically hindered ketones are also thioacetalized in excellent yields with stoic
- Sunil Kumar,Thirupathi Reddy,Narsimha Reddy,Rao,Rajitha
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p. 2387 - 2389
(2007/10/03)
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- Chemoselective thioacetalisation and transthioacetalisation of carbonyl compounds catalysed by tetrabutylammonium tribromide (TBATB)
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Thioacetals and thioketals of various aldehydes and ketones were obtained directly from carbonyl compounds or by a transthioacetalisation process from cyclic O,O-acetals in the presence of dithiols and a catalytic amount of tetrabutylammonium tribromide (TBATB). Chemoselective thioacetalisation of aromatic aldehydes containing an electron-donating group in the presence of an aldehyde containing an electron-withdrawing group, aldehydes in the presence of ketones, aliphatic cyclic ketones in the presence of aromatic ketones and less hindered ketones in the presence of more hindered ketones have been achieved. A cyclic acetal containing an electron-donating group has been chemoselectively transthioacetalised in the presence of an acetal having an electron-withdrawing substituent. These selectivities are due to the intrinsic reactivity of the substrate themselves and are independent of the catalyst and reaction conditions, Shorter reaction times, mild reaction conditions, stability of acid sensitive protecting groups, high efficiencies, facile isolation of the desired products and the catalytic nature of the reagent are the attractive features of the present method.
- Naik, Sarala,Gopinath, Rangam,Goswami, Mousumi,Patel, Bhisma K.
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p. 1670 - 1677
(2007/10/03)
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- The First Nonthiolic, Odorless 1,3-Propanedithiol Equivalent and Its Application in Thioacetalization
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2-[2-Chloro-1-(1-chlorovinyl)allylidene]-1,3-dithiane 1 was synthesized by the chlorination of 3-(1,3)-dithianylidenepentane-2,4-dione 2 using the Vilsmeier-Haack reagent in 99% yield. As a novel nonthiolic, odorless 1,3-propane-dithiol equivalent, 1 was investigated in the thioacetalization reaction. Various types of aldehydes and ketones 3 were converted to the corresponding dithianes 4 in the presence of 1 in high yields (79-97%). Moreover, 1 exhibited obvious chemoselectivity between aldehyde and ketone in this thioacetalization reaction. A mechanism for this thioacetalization reaction is proposed.
- Liu, Qun,Che, Guangbo,Yu, Haifeng,Liu, Yingchun,Zhang, Jingping,Zhang, Qian,Dong, Dewen
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p. 9148 - 9150
(2007/10/03)
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- 1,3-Dithienium and 1,3-Dithiolenium Salts, VI. - N,N-Disubstituted 4-Aminobenzophenones from 1,3-Dithian- and 1,3-Dithiolan-2-ylium Tetrafluoroborates, respectively
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The 1,3-dithienium- and 1,3-dithiolenium tetrafluoroborates 3 (n =3, 2), respectively, react in good yields with the N,N-dialkylarylamines 4 to give the 2,2-disubstituted cyclic dithio acetals 5, which can be converted after dethioacetalization with HgCl2/HgO into the ketones 7.
- Stahl, Ingfried
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p. 135 - 140
(2007/10/02)
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