1927-62-4Relevant academic research and scientific papers
Phosphorus pentoxide as an efficient catalyst for the tetrahydropyranylation of alcohols under solvent-free conditions
Eshghi, Hossein,Shafieyoon, Parvaneh
, p. 2149 - 2152 (2004)
A facile and efficient method for the preparation of tetrahydropyranyl ethers from alcohols is improved in solvent-free media. These reactions are catalyzed by P2O5 and afford various tetrahydropyranyl ethers in shorter reaction time, with good to excellent yields (75-95%) at room temperature. This method is also compatible with substrates containing acid-sensitive functional groups.
Efficient role of ionic liquid (bmim)HSO4 as novel catalyst for monotetrahydropyranylation of diols and tetrahydropyranylation of alcohols
Singh, Jasvinder,Gupta, Neeraj,Kad, Goverdhan L.,Kaur, Jasamrit
, p. 2893 - 2900 (2006)
A simple procedure for the monotetrahydropyranylation of diols and alcohols, in excellent to moderate yields, has been reported using a catalytic amount of the acidic ionic liquid, 1-butyl-3-methylimidazolium hydrogensulphate (bmim)HSO4 under microwave and ultrasonic irradiation. Results have been compared with those obtained by reactions in the absence of these energies, and effectiveness of the recycled ionic liquid has also been studied. Copyright Taylor & Francis Group, LLC.
2,3-Dichloro-5,6-dicyano-p-benzoquinone as a Mild and Efficient Catalyst for the Tetrahydropyranylation of Alcohols
Tanemura, Kiyoshi,Horaguchi, Takaaki,Suzuki, Tsuneo
, p. 304 - 305 (1992)
Hydroxy compounds readily add to 3,4-dihydro-2H-pyran under neutral conditions in the presence of a catalytic amount of 2,3-dichloro-5,6-dicyano-p-benzoquinone, to give high yields of the corresponding tetrahydropyranyl ethers.
Bis [trinitratocerium (IV)] chromate [ce(NO3)2 Cro4] and tris [trinitratocerium (IV)] paraperiodate [(No3)3Ce]3 H2IO6. Two mild and efficient catalysts for tetrahydrop
Oskooie,Abaszadeh,Zamani,Heravi
, p. 2281 - 2285 (1998)
The tetrahydropyranyl derivatives of variety of alcohols are efficiently prepared in the presence of catalytic amounts of [Ce(NO3)2CrO4] and [(NO3)3 Ce]3 H21O6 in mild
Mild and efficient tetrahydropyranylation of alcohols and dehydropyranylation of THP ethers catalyzed by ferric perchlorate
Heravi, Majid M.,Behbahani, Farahnaz K.,Oskooie, Hossien A.,Shoar, Rahim Hekmat
, p. 2543 - 2545 (2005)
A simple, mild and efficient method for tetrahydropyranylation and dehydropyranylation of alcohols in the presence of ferric perchlorate are described.
Envirocat EPZG as a new heterogenous catalyst for the solvent-free tetrahydropyranylation of alcohols and phenols
Bandgar,Jagtap,Aghade,Wadgaonkar
, p. 2211 - 2215 (1995)
Envirocat EPZG was used as a solid supported acid catalyst for tetrahydropyranylation of alcohols and phenols in the absence of a solvent. This new method is rapid, efficient and convenient giving the corresponding products in high yields and purity.
Comparison of the efficiency of two dicationic ionic liquids catalysts based on perchloric acid for the protection of alcohols
Rahmanzadeh, Akram,Daneshvar, Nader,Shirini, Farhad,Tajik, Hassan
, p. 3295 - 3302 (2021/05/13)
In this article, two aliphatic and aromatic types of dicationic acidic ionic liquids formulated as [H2-DABCO][ClO4], [H2-Bisim][ClO4]2 were used for the acceleration of the protection of alcohols as t
Fully recyclable Br?nsted acid catalyst systems
Watson, Christopher B.,Kuechle, Adrianna,Bergbreiter, David E.
, p. 1266 - 1273 (2021/02/26)
Homogeneous and heterogeneous sulfonic acid catalysts are some of the most common catalysts used in organic chemistry. This work explores an alternative scheme using a fully recyclable polymeric solvent (a poly-α-olefin (PAO)) and soluble PAO-anchored polyisobutylene (PIB)-bound sulfonic acid catalysts. This PAO solvent is nonvolatile and helps to exclude water by its nonpolar nature which in turn drives reactions without the need for distillation of water, avoiding the need for excess reagents. This highly nonpolar solvent system uses polyisobutylene (PIB) bound sulfonic acid catalysts that are phase-anchored in solvents like PAO. The effectivenes of these catalysts was demonstrated by their use in esterifications, acetalizations, and multicomponent condensations. These catalysts and the PAO solvent phase show excellent recyclability in schemes where products are efficiently separated. For example, this non-volatile polymeric solvent and the PIB-bound catalyst can be recycled quantitatively when volatile products are separated and purified by distillation. In other cases, product purification can be effected by product self-separation or by extraction.
A facile and versatile electro-reductive system for hydrodefunctionalization under ambient conditions
Huang, Binbin,Guo, Lin,Xia, Wujiong
supporting information, p. 2095 - 2103 (2021/03/26)
A general electrochemical system for reductive hydrodefunctionalization is described, employing the inexpensive and easily available triethylamine (Et3N) as a sacrificial reductant. This protocol is characterized by facile operation, sustainable conditions, and exceptionally wide substrate scope covering the cleavage of C-halogen, N-S, N-C, O-S, O-C, C-C and C-N bonds. Notably, the selectivity and capability of reduction can be conveniently switched by simple incorporation or removal of an alcohol as a co-solvent.
Highly selective tetrahydropyranylation/dehydropyranylation of alcohols and phenols using porous phenolsulfonic acid-formaldehyde resin catalyst under solvent-free condition
Rajkumari, Kalyani,Laskar, Ikbal Bahar,Kumari, Anupama,Kalita, Bandita,Rokhum, Lalthazuala
, (2020/02/18)
An efficient protocol for solvent-free chemoselective tetrahydropyranylation/depyranylation of alcohols and phenols is reported herein using mesoporous Phenolsulfonic Acid Formaldehyde Resins as a heterogeneous acid catalyst. The catalyst successfully performed chemoselective protection and deprotection reactions of a wide range of substrates ranging from primary to secondary and tertiary alcohols and also phenols. The reactions were carried out at ambient temperature under solvent-free condition (SolFC) which resulted in high yields within a very short time. FT-IR, TEM, SEM, EDS and TG-DSC analysis techniques were employed to characterize the synthesized polymeric catalyst. The chemoselective nature of our method was confirmed using 13C DEPT-135 NMR studies. The polymer catalyst was found to be recoverable even after 10th catalytic cycle without much depreciation in its activity. The heterogeneity of the catalyst was verified by hot filtration method. Good yield, energy and cost- effective method, solvent-free protocol, mild reaction conditions, no inert atmosphere, metal-free heterogeneous polymer catalyst and excellent recoverability of the catalyst are notable milestones of the reported protocol.
