7401-52-7Relevant academic research and scientific papers
Selective Synthesis of Acylated Cross-Benzoins from Acylals and Aldehydes via N-Heterocyclic Carbene Catalysis
Onodera, Kou,Suzuki, Yumiko,Takashima, Ryo
supporting information, 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.
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.
SiO2@FeSO4 nano composite as nanocatalyst for the green synthesis 1,1-diacetates from aldehydes under solvent-free conditions
KarimKoshteh, Mostafa,Bagheri, Marziyeh,Zeynizadeh, Behzad
, p. 2780 - 2783 (2016/07/12)
Aldehydes compounds selective converted to 1,1-diacetates as protective reagent with SiO2@FeSO4 nano composite as effective nano catalyst at room temperature under solvent-free condition and acetic anhydride (Ac2O) as acet
Preparation of 1,1-diacetates from aldehydes by LiBH4 and Ac2O in the presence of cation exchange resin
Rezaeekhordehforosh, Reza,Khezri, Behrooz,Setamdideh, Davood
, p. 1205 - 1209 (2015/10/28)
A variety of 1,1-diacetates have been produced from the corresponding aldehydes (1 mmol) by LiBH4(1.25 mmol) and Ac2O (1 mL) in the presence of DOWEX(R)50WX4 (0.5 g) as a cation exchange resinwithin 10 min at room temperature with excellent yields of the products (93-97%).
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.
Solvent-free Chemoselective Synthesis of 1,1-diacetates Catalyzed by Iron Zirconium Phosphate
Karimi, Hirbod
, p. 1000 - 1010 (2015/12/01)
In the present study, a mild, rapid, and efficient method for the protection of aldehydes with acetic anhydride (AA) in the presence of iron zirconium phosphate (ZPFe), 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. The catalyst 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-friendly catalyst, chemoselectivity, simple experimental and work-up procedure, solvent-free conditions and only a stoichiometric amount of AA is needed.
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.
NaBH4/Ac2O/DOWEX(R)50WX4: A convenient system for fast preparation of gem-diacetates from aldehydes
Asl, Parisa Azizi,Setamdideh, Davood
, p. 940 - 944 (2014/10/16)
Reductive-acylalation of aldehydes has been carried out by NaBH 4/Ac2O/DOWEX(R)50WX4 system. A variety of aldehydes (1 mmol) have been reacted with Ac2O (0.5 mL) and NaBH4 (1 mmol) in the presence of DOWEX(R)50WX4 (0.5 g) for the preparation of their corresponding acylals within 1 min at room temperature with excellent yields of the products (90-95%). Ketones do not react with this system.
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.
