6345-63-7Relevant academic research and scientific papers
Chemoselective synthesis of 1,1-diacetates under solvent-free condition using efficient heterogeneous ecofriendly catalyst: P2O5/kaolin
Rai, Nityanand,Sharma, Abha
, p. 340 - 344 (2019/05/21)
An efficient and chemoselective method for the preparation of acylals from different aldehydes and acetic anhydride using.....kaolin supported catalyst (P2O5). under solvent-free conditions is described herein. The present protocol offers several advantages including use of inexpensive and non-toxic catalyst support i.e., natural kaolin. Preparation of the supported catalyst is easy, the process is simple in operation, maintaining solvent free conditions, with short reaction times, high yields and affording selective protection of aldehyde in presence of ketone.
N-Propylsulfamic acid supported onto magnetic Fe3O4 nanoparticles (MNPs-PSA) as a green and reusable heterogeneous nanocatalyst for the chemoselective preparation and deprotection of acylals
Sajjadifar, Sami,Nasri, Parastoo
, p. 6677 - 6689 (2017/10/06)
Abstract: N-propylsulfamic acid supported onto magnetic Fe3O4 nanoparticles (MNPs-PSA) was simply synthesized and used as a highly efficient, environmentally friendly, and chemoselective catalyst for the synthesis of 1,1-diacetates (acylals) from the one-pot condensation reaction of various aromatic aldehydes with acetic anhydride, in high yield of products (86–96%) and short reaction time (20–60?min) under solvent-free conditions at room temperature. In addition to these results, we further studied the possibility of deprotection of the resulting acylals into benzaldehyde derivatives in this catalytic system by the addition of water. More importantly, noteworthy advantages of this study are non-use of toxic organic solvents and catalysts, simple work-up procedure, short reaction time, high yield of products, and recovery and reusability of MNPs-PSA by an external magnet. Graphical Abstract: A simple and highly efficient procedure for the protection of various aldehydes with acetic anhydride in the presence of N-propylsulfamic acid supported onto magnetic Fe3O4 nanoparticles (MNPs-PSA) is reported. We further studied the possibility of deprotection of the resulting acylals into benzaldehyde derivatives in this catalytic system by the addition of water as a green solvent. The catalyst was reused several times without loss of its catalytic activity.
Supported N-propylsulfamic acid onto Fe3O4 magnetic nanoparticles as a reusable and efficient nanocatalyst for the protection/deprotection of hydroxyl groups and protection of aldehydes
Rostami, Amin,Tahmasbi, Bahman,Abedi, Fatemeh
, p. 3689 - 3701 (2016/04/05)
N-propylsulfamic acid supported onto Fe3O4 magnetic nanoparticles (MNPs-PSA) as an efficient and magnetically reusable nanocatalyst has been reported for the tetrahydropyranylation/depyranylation of a wide variety of alcohols and phenols by changing the solvent medium. Also, the protection of aldehydes as acylals using Ac2O in the presence of catalytic amount MNPs-PSA in good to high yields at room temperature under solvent-free conditions is described. After completing the reaction, the catalyst was easily separated from the reaction mixture with the assistance of an external magnetic field and reused for several consecutive runs without significant loss of their catalytic efficiency.
Synthesis of 1,1-diacetates catalyzed by cellulose sulfonic acid from aldehydes and acetic anhydride
Ding, Songsong,Zhang, Jiming,Shi, Wei,Zhou, Jianhua
, p. 340 - 342 (2015/02/19)
1,1-Diacetates have been synthesized in good to excellent yields via a reaction of corresponding aldehydes and acetic anhydride in the presence of cellulose sulfonic acid as a heterogeneous catalyst at room temperature. The protection of aldehydes generated an anhydrodimer as single product under similar reaction conditions. The catalysis is equally applicable for the deprotection of acylal in acetonitrile.
Zinc zirconium phosphate as an efficient catalyst for chemoselective synthesis of 1,1-diacetates under solvent-free conditions
Hajipour, Abdol R,Karimi, Hirbod
, p. 1945 - 1955 (2015/12/30)
In the present study, a mild, rapid, and efficient method for the protection of aldehydes with acetic anhydride (AA) in the presence of zinc zirconium phosphate (ZPZn) as a nano catalyst, at room temperature is reported. Selective conversion of aldehydes was observed in the presence of ketones. Under these conditions, different aldehydes bearing electron-withdrawing and electron-donating substituents were reacted with AA and the corresponding 1,1-diacetates (acylals) were obtained in high to excellent yields. The steric and electronic properties of the different substrates had a significant influence on the reaction conditions. Also, the deprotection of 1,1-diacetates has been achieved using this catalyst in water. This nanocatalyst was characterized by several physico-chemical techniques. It was recovered easily from the reaction mixture, regenerated and reused at least 7 times without significant loss in catalytic activity. This protocol has the advantages of easy availability, stability, reusability of the eco-friendliness, chemoselectivity, simple experimental and work-up procedure, solvent-free conditions and usage of only a stoichiometric amount of AA.
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.
Functionalized Poly(Amidoamine) Dendrimer as a Strong Ionic Br?nsted Acid Organocatalyst for Protection/Deprotection of Aldehydes
Pourjavadi, Ali,Hosseini, Seyed Hassan
, p. 1794 - 1801 (2015/10/29)
Poly(amidoamine) dendrimer (PAMAM) was successfully functionalized by chlorosulfonic acid to form an strong ionic acid catalyst. The resulting polymeric catalyst was shown to be an efficient catalyst for the synthesis of 1,1-diacetyl from aldehydes under free solvent conditions at room temperature. Also, the deprotection of the resulting aldehydes was investigated under catalytic conditions. The Hammett acidity function of catalyst showed that catalyst is a strong Br?nsted acid. Due to the multi-functional nature of PAMAM, the catalyst has high loading level of acidic protons.
P4VP-H2SO4-catalyzed chemoselective protection of aldehydes to acylal along with deprotection reactions
Dutta, Papia,Sarma, Parishmita,Borah, Ruli
, p. 1378 - 1386 (2013/05/09)
Poly(4-vinylpyridine)-supported sulfuric acid is an excellent reusable heterogeneous catalyst for the chemoselective synthesis of 1,1- diacetates(acylal) from aldehydes in dichloromethane at room temperature within a few minutes. The protection of salicyaldehyde generated an anhydro-dimer as single product under similar reaction conditions. The catalyst is equally applicable for the deprotection of acylal in acetonitrile. The catalyst was prepared by the wet impregnation technique.
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.
