- Visible-Light-Induced in Situ Generation of Fischer-Type Copper Carbene Complexes from Acylsilanes and Its Application to Catalytic [4 + 1] Cycloaddition with Siloxydienes
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A novel methodology for in situ generation of Fischer-type metal–carbene complexes was developed. Photoirradiation to a mixture of an acylsilane and a cationic copper complex cleanly gave a Fischer-type copper–siloxycarbene complex, which was detected by spectroscopic methods. This carbene complex reacted with siloxydienes in a [4 + 1] cycloaddition manner to give cyclopentene derivatives. It is noteworthy that this reaction proceeds with a catalytic amount of copper through in situ generation of a Fischer-type copper–siloxycarbene complex intermediate.
- Takeuchi, Taiichi,Aoyama, Tsukasa,Orihara, Kurumi,Ishida, Kento,Kusama, Hiroyuki
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supporting information
p. 9490 - 9494
(2021/12/14)
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- Dehydrative Glycosylation Enabled by a Comproportionation Reaction of 2-Aryl-1,3-dithiane 1-Oxide?
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A new dehydrative glycosylation reaction has been established by capitalizing on the comproportionation reaction of 2-aryl-1,3-dithiane 1-oxides promoted by triflic anhydride (Tf2O). By wedding the high potency of thiophilic promoter system with the step efficiency of dehydrative glycosylation, this reagent underwent facile intermolecular oxothio acetalization with C1-hemiacetal donor to install a temporary leaving group, rendering a transient electrophilic center at the remote site to the anomeric position. The sulfenyl triflate tethered at the terminus concomitantly activated the sulfide intramolecularly to afford the oxocarbenium ion, thereby facilitating the title glycosylation. Aside from accommodating broad range functional groups and inactive hemiacetal substrates, the present activation protocol also proved expedient for 1,3-diol protection. Most importantly, this method further provided a fresh perspective for the application of sulfur chemistry to carbohydrate chemistry.
- Cai, Lei,Zeng, Jing,Li, Ting,Xiao, Ying,Ma, Xiang,Xiao, Xiong,Zhang, Qin,Meng, Lingkui,Wan, Qian
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supporting information
p. 43 - 49
(2019/11/28)
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- Synthesis of Chiral α-Aminosilanes through Palladium-Catalyzed Asymmetric Hydrogenation of Silylimines
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The asymmetric hydrogenation of silylimines was first developed by using a palladium complex of a P-stereogenic diphosphine ligand as the catalyst, affording the valuable chiral α-aminosilanes with quantitative conversions and excellent enantioselectiviti
- Fan, Dongyang,Liu, Yang,Jia, Jia,Zhang, Zhenfeng,Liu, Yangang,Zhang, Wanbin
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supporting information
p. 1042 - 1045
(2019/05/16)
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- Nickel-Catalyzed Synthesis of Silanes from Silyl Ketones
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An unprecedented nickel-catalyzed decarbonylative silylation via CO extrusion intramolecular recombination fragment coupling of unstrained and nondirecting group-Assisted silyl ketones is described. The inexpensive and readily available catalyst performs
- Srimontree, Watchara,Lakornwong, Waranya,Rueping, Magnus
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supporting information
p. 9330 - 9333
(2019/11/19)
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- A 2 - substituted - 1, 3 - dithiane derivative of the preparation method
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The invention provides a preparation method of a 2-substituted-1,3-dithiane derivative. The preparation method comprises the following steps: adding 1,3-dithiane (CAS:505-23-7) and 1,2-dichloroethane (DCE) or dichloromethane (DCM) into a reaction bottle, adding N-chlorosuccinimide (NCS) under ice-bath condition, and stirring for 0.5-1 h to prepare a 2-chloro-1,3-dithiane solution; and adding an aldehyde or ketone compound and a lewis acid catalyst into the above solution, and reacting to prepare the 2-substituted-1,3-dithiane derivative. By using the 1,3-dithiane solid and different types of aldehyde and keto-carbonyl compounds as raw material and using one or more of ferric trichloride, boron trifluoride diethyl etherate, methanesulfonic acid, aluminum trichloride, ferrous chloride and nickel chloride as catalysts, preparation of the 2-substituted-1,3-dithiane derivative is realized. The catalysts used in the invention are cheap and easily available, dosage of the catalysts is low and pollution of the catalysts is little. The solid raw materials used in the invention can avoid use of fetid toxic 1,3-dimercaptopropane with strong volatility, and the purpose of protecting an experimenter's body and reducing environmental pollution is realized. In addition, the preparation method has advantages of mild reaction condition, high yield, simple operation and the like.
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Paragraph 0023; 0024; 0025; 0026; 0027
(2019/06/26)
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- Visible-light promoted dithioacetalization of aldehydes with thiols under aerobic and photocatalyst-free conditions
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A novel photocatalyst-free visible-light-mediated dithioacetalization of aldehydes and thiols has been developed. This protocol is operationally simple, mild and atom-economical, which provides an environmental benign access to dithioacetals at room temperature under aerobic conditions.
- Xing, Zhimin,Yang, Mingyang,Sun, Haiyu,Wang, Zemin,Chen, Peng,Liu, Lin,Wang, Xiaolei,Xie, Xingang,She, Xuegong
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supporting information
p. 5117 - 5122
(2018/11/24)
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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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- Lewis Acid-Assisted Photoinduced Intermolecular Coupling between Acylsilanes and Aldehydes: A Formal Cross Benzoin-Type Condensation
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Intermolecular carbon–carbon bond-forming reaction between readily available acylsilanes and aldehydes was achieved under photoirradiation conditions with assistance of a catalytic amount of Lewis acid. Nucleophilic addition of photochemically generated s
- Ishida, Kento,Tobita, Fumiya,Kusama, Hiroyuki
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supporting information
p. 543 - 546
(2017/12/07)
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- Preparing method of 2-substituted-1,3-dithiane derivative
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The invention belongs to the technical field of organic synthesis, and particularly discloses a preparing method of a 2-substituted-1,3-dithiane derivative. The preparing method comprises the following steps of adding substrate aldehyde, 1,3-dimercaptopro
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Paragraph 0020-0026; 0039-0041
(2018/10/02)
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- Sulfur-Directed Ligand-Free C-H Borylation by Iridium Catalysis
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An iridium-catalyzed ortho C-H borylation reaction directed by cyclic dithioacetal moiety is disclosed. A series of borylation products were obtained in moderate to good yields under mild conditions in exclusive mono- and ortho-regioselectivity. Thus, the 1,3-dithiane or 1,3-dithiolane group serves as a remarkable effective directing group for C-H borylation without any ligand assistance. The further transformations of the borylation products are also carried out to change boryl group to other functional groups.
- Liu, Li,Wang, Guanghui,Jiao, Jiao,Li, Pengfei
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supporting information
p. 6132 - 6135
(2017/11/24)
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- Oxidative [1,2]-Brook Rearrangements Exploiting Single-Electron Transfer: Photoredox-Catalyzed Alkylations and Arylations
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Oxidative [1,2]-Brook rearrangements via hypervalent silicon intermediates induced by photoredox-catalyzed single-electron transfer have been achieved, permitting the formation of reactive radical species that can engage in alkylations and arylations.
- Deng, Yifan,Liu, Qi,Smith, Amos B.
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supporting information
p. 9487 - 9490
(2017/07/24)
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- Aluminum hydrogen sulfate [Al(HSO4)3] as an efficient catalyst for the preparation of thioacetals
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Aluminum hydrogen sulfate, as a heterogeneous solid acid catalyst, has been used for the mild conversion of carbonyl compounds to their thioacetals using 1,2- and 1,3-dithiol under ambient conditions with short reaction times in high to excellent yield in
- Ghashang, Majid
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p. 2837 - 2842
(2013/07/26)
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- SBA-15 functionalized sulfonic acid containing a confined hydrophobic and acidic ionic liquid: A highly efficient catalyst for solvent-free thioacetalization of carbonyl compounds at room temperature
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A novel application of SBA-15 functionalized sulfonic acid containing a confined ionic liquid has been introduced to convert various carbonyl compounds to their corresponding dithioacetals and dithioketals at room temperature and under solvent-free condit
- Karimi, Babak,Vafaeezadeh, Majid
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p. 23207 - 23211
(2013/11/19)
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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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- Chemoselective dithioacetalization of carbonyl compounds using magnesium hydrogensulfate as efficient heterogeneous catalyst
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Carbonyl compounds have been successfully converted into their corresponding dithiolanes and dithianes derivatives with 1,2-ethanedithiol and 1,3-propanedithiol in excellent yield at room temperature and short reaction times using a catalytic amount of ma
- Shaterian, Hamid Reza,Hosseinian, Asghar,Ghashang, Majid,Khorami, Fahimeh
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experimental part
p. 2490 - 2501
(2009/08/07)
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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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- Chemoselective thioacetalization with odorless 2-(1,3-dithian-2-ylidene)-3- oxobutanoic acid as a 1,3-propanedithiol equivalent
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Odorless 2-(1,3-dithian-2-ylidene)-3-oxobutanoic acid (1c) was prepared and investigated in the thioacetalization of carbonyl compounds as a 1,3-propanedithiol equivalent. The results showed that the thioacetalization of various carbonyl compounds 2 with 1c proceeded smoothly and afforded the corresponding dithioacetals 3 in high yields (up to 99%) in the presence of acetyl chloride at room or reflux temperatures. Moreover, the thioacetalization exhibited high chemoselectivity between aldehydes and ketones.
- Yu, Haifeng,Dong, Dewen,Ouyang, Yan,Liu, Qun
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p. 1741 - 1745
(2007/10/03)
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- α,α-diacetyl cyclic ketene dithioacetals: Odorless and efficient dithiol equivalents in thioacetalization reactions
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Two novel, non-thiolic, odorless dithiol equivalents, α,α- diacetyl cyclic ketene dithioacetals 2a and 2b, had been developed. A range of carbonyl compounds 3 were converted into corresponding dithioacetals, dithianes 4 and dithiolanes 5, in high yields (up to 99%) in the presence of 2a or 2b. Moreover, 2a and 2b show high chemoselectivity between aldehyde and ketone in thioacetalization.
- Yu, Haifeng,Liu, Qun,Yin, Yanbing,Fang, Qunxin,Zhang, Jingping,Dong, Dewen
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p. 999 - 1002
(2007/10/03)
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- NOVEL DITHIOKETAL
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A novel compound of formula (I) and a process for the preparation of compounds of formula (I): by reacting a compound of formula (II): Formula (III): with a compound of formula (III) where R1 and R2 are any suitable alkyl group, preferably C2H5 or R1 and R2 can join together to form any cyclic structure, preferably -CH2-Ch2-CH2-.
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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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- Scandium triflate as a recyclable catalyst for chemoselective thioacetalization
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Scandium triflate [Sc(OTf)3] has been found to be an extremely efficient and recyclable catalyst for the addition of ethanethiol, 1,2-ethanedithiol and 1,3-propanedithiol to both aromatic and aliphatic aldehydes. In addition, by employing this catalyst, high chemoselective thioacetalization of carbonyl compounds has been achieved.
- Kamal, Ahmed,Chouhan, Gagan
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p. 1347 - 1350
(2007/10/03)
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- A convenient preparation of symmetrical and unsymmetrical 1,2-diketones: Application to fluorinated phenytoin synthesis
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1,2-Diketones are efficiently produced in two steps by reaction of aldehydes with anions derived from 2-substituted dithianes followed by treatment of the resulting alcoholis with NBS in aqueous acetone; phenytoin derivatives were prepared from these diketones by a standard method involving treatment with urea and potassium hydroxide under reflux.
- Page,Graham,Park
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p. 7265 - 7274
(2007/10/02)
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