20803-88-7Relevant academic research and scientific papers
Poly(4-vinylpyridinium) perchlorate as an efficient solid acid catalyst for the chemoselective preparation of 1,1-diacetates from aldehydes under solvent-free conditions
Khaligh, Nader Ghaffari
, p. 329 - 334 (2014/04/03)
Poly(4-vinylpyridinium) perchlorate has been used as a supported, recyclable, environmentally-benign catalyst for the formation of acylals from aliphatic and aromatic aldehydes in good to excellent yields under solvent-free conditions. Notably, the reaction conditions were tolerant of ketones. This methodology offers several distinct advantages, including its operational simplicity and high product yield, as well as being green in terms of avoiding the use of toxic catalysts and solvents. Furthermore, the catalyst can be recovered and reused several times without any loss in its activity.
Polystyrene-supported TiCl4 as a novel, efficient and reusable polymeric Lewis acid catalyst for the chemoselective synthesis and deprotection of 1,1-diacetates under eco-friendly conditions
Rahmatpour, Ali,Mohammadian, Sara
, p. 912 - 919 (2013/10/22)
Copolymer beads of styrene and divinylbenzene (5-7%) were synthesized and combined with titanium tetrachloride in CS2 to form a stable complex. The PS/TiCl4 complex was used as a mild and efficient polymer-supported Lewis acid catalyst for the preparation of 1,1-diacetates from various types of aldehydes under heterogeneous conditions at room temperature. Deprotection of the resulting 1,1-diacetates has also been achieved using the same catalyst in methanol. This new protocol has the advantages of easy availability, stability, reusability of the eco-friendly catalyst, high to excellent yields, chemoselectivity, simple experimental and work-up procedure. Moreover, this polymeric catalyst could be recovered easily and reused several times without significant loss in activity.
Ultrasound assisted the chemoselective 1,1-diacetate protection and deprotection of aldehydes catalyzed by poly(4-vinylpyridinium)hydrogen sulfate salt as a eco-benign, efficient and reusable solid acid catalyst
Khaligh, Nader Ghaffari,Shirini, Farhad
, p. 19 - 25 (2013/01/15)
Poly(4-vinylpyridinium) hydrogen sulfate solid acid was found to be efficient catalyst for preparation of 1,1-diacetate using ultrasound irradiation at ambient temperature and neat condition. Deprotection of the resulting 1,1-diacetates were achieved using the same catalyst in methanol solvent under ultrasound irradiation at room temperature. This new method consistently has the advantage of excellent yields and short reaction times. Utilization of solvent free, simple reaction conditions, isolation, and purification makes this manipulation very interesting from an economic and environmental perspective. Further, the catalyst can be reused and recovered for several times.
A succinimide-N-sulfonic acid catalyst for acetylation reactions in absence of a solvent
Shirini, Farhad,Khaligh, Nader Ghaffari
, p. 695 - 703 (2013/08/25)
A small amount of succinimide-N-sulfonic acid efficiently catalyzed the acetylation of a variety alcohols, phenols, thiols, amines and aldehydes with acetic anhydride at room temperature under solvent free conditions. This catalyst has the advantages of excellent yields and short reaction times and the reaction can be carried out on a large scale, which makes it potentially useful for industrial applications.
Introduction of N-sulfonic acid poly(4-vinylpyridinum) chloride as an efficient and reusable catalyst for the chemoselective 1,1-diacetate protection and deprotection of aldehydes
Shirini, Farhad,Jolodar, Omid Goli
experimental part, p. 61 - 69 (2012/04/17)
N-sulfonic acid poly(4-vinylpyridinium) chloride is easily prepared by the reaction of poly(4-vinylpyridine) with neat chlorosulfonic acid. This reagent can be used as an efficient catalyst for the preparation of 1,1-diacetates at room temperature and neat condition. Deprotection of the resulting 1,1-diacetates can also be achieved using the same catalyst in methanol. This new method consistently has the advantages of excellent yields and short reaction times. Further, the catalyst can be reused and recovered for several times.
An efficient and chemoselective procedure for acylal synthesis
Fan, Da-He,Wang, Hui,Mao, Xing-Xing,Shen, Yong-Miao
experimental part, p. 6493 - 6501 (2010/11/04)
A novel heterogeneous efficient procedure has been developed for the chemoselective synthesis of acylals (1,1-diacetates) under solvent-free conditions. A novel catalyst prepared by the sulfuric acid catalyzed copolymerization of p-toluenesulfonic acid and paraformaldehyde displays extremely high activities for the title reactions, affording average yields over 90% within several minutes. A comparative study showed that the novel catalyst has much higher activity than other catalysts used for this purpose. Besides, the novel catalyst displays chemoselectivity for the protection of aldehydes in the presence of ketones. In addition the high acidity (4.0 mmol/g), thermal stability (200 °C) and easy reusability make the novel catalyst one of the best choices for the process.
Bis(NHC)-palladium(II) complex-catalyzed dioxygenation of alkenes
Wang, Wenfeng,Wang, Feijun,Shi, Min
experimental part, p. 928 - 933 (2010/05/01)
Bis(NHC)-Pd(II) complexes derived from l,l'-binaphthyl-2,2'-diamine (BINAM) were successfully first used to catalyze the dioxygenation of alkenes under mild conditions tolerant of air and moisture. Cationic NHC-Pd2+ diaquo complex 1e showed the highest catalytic activity to give 1,2dioxygenation products with good syn-diastereoselectivity for 1,2-disubstituted alkenes.
Copper-catalyzed diacetoxylation of olefins using PhI(OAc)2 as oxidant
Seayad, Jayasree,Seayad, Abdul Majeed,Chai, Christina L. L.
scheme or table, p. 1412 - 1415 (2010/06/13)
(Figure Presented) Copper(I) or -(II) salts with weakly coordinating anions catalyze the diacetoxylation of olefins efficiently In the presence of PhI(OAc)2 as the oxidant under mild conditions. The reaction is effective for aryl, aryl alkyl, as well as aliphatic terminal and internal olefins forming the corresponding vicinal diacetoxy compounds In 70-85% yields and dr (syn/anti) of up to 5.2. Under these conditions, homoallylic alcohols formed the corresponding tetrahydrofuran derivatives in high yields.
Chloroferrate(III) ionic liquid as recyclable catalyst for the acetylation of alcohols and phenols and for 1,1-Diacylation of aldehydes
Wanga, Dong-Sheng,Lib, Gui-Yun,Pengb, Yan-Qing
experimental part, p. 834 - 838 (2010/08/13)
A Lewis acidic ionic liquid, [bmim][FeCl4], was employed to catalyze acetylation of alcohols and phenols, and the conversion of aldehydes to corresponding 1,1-diacetates without conventional organic solvents. The catalyst is easily available, water-tolerant, recoverable and easy to handle.
Synthesis of 1,1-diacetates using a new combined catalytic system: Copper p-toluenesulfonate/HOAc
Wang, Min,Song, Zhiguo,Gong, Hong,Jiang, Heng
, p. 961 - 966 (2008/09/17)
Copper p-toluenesulfonate acetic acid has been established as an efficient combined catalytic system for chemoselective conversion of aldehydes to diacetates in high yields at ambient temperature in short reaction times. For the catalytic system, the amount of copper p-toluenesulfonate reduced to 0.3 mol%. After the reaction, copper p-toluenesulfonate can be easily recovered and reused for at least 10 runs. Copyright Taylor & Francis Group, LLC.
