574-06-1Relevant academic research and scientific papers
(2-Fluoroallyl)boration of Ketones with (2-Fluoroallyl)boronates
Novikov, Maxim A.,Bobrova, Angelina Yu.,Mezentsev, Igor A.,Medvedev, Michael G.,Tomilov, Yury V.
, p. 6295 - 6308 (2020)
Efficient routes toward activation of gem-chlorofluorocyclopropane-derived (2-fluoroallyl)boronates for allylboration of various ketones including functionalized and low-reactive ones were developed. Increasing the boron electrophilicity by the transforma
Noncross-linked polystyrene nanoencapsulation of ferric chloride: A novel and reusable heterogeneous macromolecular Lewis acid catalyst toward selective acetylation of alcohols, phenols, amines, and thiols
Alinejad, Sara,Donyapeyma, Ghazaleh,Rahmatpour, Ali
, (2022/01/24)
Ferric chloride has been successfully nanoencapsulated for the first time on a non-cross-linked polystyrene matrix as the shell material via the coacervation technique. The resulting polystyrene nanoencapsulated ferric chloride was used as a novel and rec
Selective Synthesis of Acylated Cross-Benzoins from Acylals and Aldehydes via N-Heterocyclic Carbene Catalysis
Onodera, Kou,Suzuki, Yumiko,Takashima, Ryo
, p. 4197 - 4202 (2021/06/27)
The utility of acylals as building blocks for selective cross-benzoin synthesis was explored in this study. The synthesis of α-acetoxyketones (O-acyl cross-benzoins) was achieved via selective N-heterocyclic carbene-catalyzed cross-benzoin reactions using acylals as aldehyde equivalents. Thus, the combination of ortho-substituted phenyl acylals and aromatic/aliphatic aldehydes as coupling substrates using bicyclic triazolium salts as precatalysts and potassium carbonate as a base in THF at reflux temperature selectively yielded O-acyl cross-benzoins.
Synthesis of task-specific imidazolium ionic liquid as an efficient catalyst in acetylation of alcohols, phenols, and amines
Chaubey, Snehkrishn A.,Mishra, Roli
, p. 3259 - 3268 (2020/04/17)
Herein, we report the synthesis of task-specific amino-functionalized imidazolium ionic liquid, acetate1-(2-tert-butoxycarbonylamino-ethyl)-3-methyl-3H-imidazol-1-ium; (Boc-NH-EMIM.OAc), as an efficient catalyst for the acetylation of alcohols, phenols, and amines in the presence of acetic anhydride (acetylating reagent). Remarkably, acetic anhydride in the presence of 10?molpercent of catalyst (Boc-NH-EMIM.OAc) under solvent-free conditions showed excellent acetylation activity in shorter duration of time. On the basis of this, a general procedure for acetylation of alcohols, phenols, and amines has been developed. The ionic liquid (Boc-NH-EMIM.OAc) can be readily recovered and reused successfully up to four consecutive cycles without any significant loss of its catalytic activity. We have been able to show that this acetylating method has many advantages. It gives high yields, takes shorter time, and develops the possibility of benign environmental-friendly process.
Sulfur-mediated difunctionalization of internal and terminal alkynes for the synthesis of α-acetoxy ketones
Li, Pingfan,Zhang, Zhong
, (2020/02/13)
The sulfur-mediated difunctionalization of alkynes is reported to give α-acetoxy ketones in a one-pot operation under mild conditions with 19–92% yield. By using wet potassium acetate as both the aqueous base and nucleophilic reagent, both terminal alkynes and internal alkynes could be converted into the α-acetoxy ketone products.
A DEVELOPING AGENT PRECURSOR FOR LASER MARKABLE COMPOSITIONS
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Paragraph 0143, (2019/01/07)
The invention relates to novel laser markable compositions comprising developing agent precursors according to formula (I).
Reusable and efficient polyvinylpolypyrrolidone-supported triflic acid catalyst for acylation of alcohols, phenols, amines, and thiols under solvent-free conditions
Tajbakhsh, Mahgol,Tajbakhsh, Mahmoud,Khaksar, Samad,Gazvini, Helia Janatian,Heidary, Marzieh
, p. 1117 - 1122 (2017/05/10)
Abstract: A triflic acid-functionalized polyvinylpolypyrrolidone was prepared and fully characterized by FT-IR, TGA, and SEM. This super acidic solid catalyst shows high catalytic activity for selective acylation of alcohols, phenols, amines, and thiols with anhydrides under solvent-free conditions at room temperature. In addition, this method features an easy to handle solid super acid catalyst and an operationally simple procedure, affording the desired acylated products in excellent yields. Graphical abstract: [Figure not available: see fulltext.].
Synthesis of β-acetoxy alcohols by PhI(OAc)2-mediated metal-free diastereoselective β-acetoxylation of alcohols
Zhao, Chun-Yang,Li, Liang-Gui,Liu, Qing-Rong,Pan, Cheng-Xue,Su, Gui-Fa,Mo, Dong-Liang
, p. 6795 - 6803 (2016/07/23)
β-Acetoxy alcohols can be synthesized in good yields with excellent diastereoselectivity from tertiary alcohols through PhI(OAc)2-mediated metal-free β-acetoxylation. Mechanistic studies showed that the β-acetoxylation process might undergo dehydration and sequential highly regioselective and diastereoseletive dioxygenation. Gram scale and diverse useful scaffolds could be prepared via this β-acetoxylation process.
Palladium-Catalyzed Chemo- and Enantioselective C?O Bond Cleavage of α-Acyloxy Ketones by Hydrogenolysis
Chen, Jianzhong,Zhang, Zhenfeng,Liu, Delong,Zhang, Wanbin
supporting information, p. 8444 - 8447 (2016/07/19)
A chemoselective C?O bond cleavage of the ester alkyl side-chain of α-acyloxy ketones was realized for the first time by a highly efficient palladium-catalyzed hydrogenolysis (S/C=6000, the highest catalytic efficiency by far). Furthermore, a kinetic resolution of α-acyloxy ketones was first developed by enantioselective hydrogenolysis with good yields and up to 99 % ee.
Visible Light Mediated Reductive Cleavage of C-O Bonds Accessing α-Substituted Aryl Ketones
Speckmeier, Elisabeth,Padié, Clément,Zeitler, Kirsten
supporting information, p. 4818 - 4821 (2015/10/12)
C-O σ-bonds in multifaceted benzoin derivatives can be effectively cleaved as acetates using catalytic amounts of [Ru(bpy)3]Cl2 as photoredox catalyst in combination with Hantzsch ester and triethylamine as a sacrificial electron donor. This mild and operationally simple method is applicable to a great variety of substrates. Homo- and cross-benzoins, which are easily accessed by NHC (N-heterocyclic carbene) catalysis, with both electron-withdrawing and electron-donating substituents, including aryl halogenides, can be employed. The deoxygenated counterparts are isolated in good to excellent yields. These broadly accessible, α-substituted (nonsymmetric) aryl ketones are versatilely applicable for further transformations as illustrated by the syntheses of 2-arylbenzofurans.
