- BiCl3: A versatile catalyst for the tetrahydropyranylation and depyranylation of 1°,2°,3°, allylic, benzylic alcohols, and symmetric diols
-
Bismuth trichloride as mild reagent, has been found to be a worthful catalyst for tetrahydropyranylation of 1°,2°,3°, allylic, benzylic alcohols, and symmetric di-ols. At room temperature the reagent THP(3,4-dihydro-2H-pyran) was successfully employed as pyranylating agent in presence of BiCl3catalyst without the use of a solvent and the yields of the products were found to be 90-96%. Further, the depyranylation of alcohols was achieved in quantitative yield by simple addition of MeOH using the same catalyst. The developed method was showed good chemo-selectivity in symmetrical diols for mono THP protection.
- Vijaya Durga,Balamurali Krishna,Baby Ramana,Santha Kumari,Vijay,Hari Babu
-
p. 1030 - 1034
(2017/05/26)
-
- Zwitterionic imidazolium salt: An efficient organocatalyst for tetrahydropyranylation of alcohols
-
An aprotic imidazole based zwitterionic-salt, 4-(3-methylimidazolium)-butane sulfonate has been found to be an efficient organocatalyst for tetrahydropyranylation by the reaction of 3,4-dihydro-2H-pyran (DHP) and different aliphatic alcohols as well as various phenolic compounds. The notable advantages of the present method are general applicability to various alcohols, clean reaction, production of no hazardous waste, open air reaction conditions and high yields. The catalyst can be reused without the loss of significant catalytic activity.
- Mahato, Sachinta,Chatterjee, Rana,Chakraborty Ghosal, Nirnita,Majee, Adinath
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supporting information
p. 1905 - 1915
(2017/10/07)
-
- Magnetic nanoparticle-supported DABCO tribromide: A versatile nanocatalyst for the synthesis of quinazolinones and benzimidazoles and protection/deprotection of hydroxyl groups
-
1,4-Diazabicyclo[2.2.2]octane tribromide supported on magnetic Fe3O4 nanoparticles (MNPs-DABCO tribromide) as a novel heterogeneous tribromide type compound was found to be an efficient and reusable nanocatalyst for the one-pot synthesis of 2-arylquinazolin-4(3H)-ones and 2-aryl-1H-benzo[d]imidazoles through oxidative cyclization of aldehydes with 2-aminobenzamides and 1,2-phenylenediamine, respectively. Also, MNPs-DABCO tribromide catalyzed trimethylsilylation/tetrahydropyranylation and desilylation/depyranylation of a wide variety of alcohols and phenols through changing the solvent medium at room temperature.
- Rostami, Amin,Pourshiani, Omid,Navasi, Yahya,Darvishi, Neda,Saadati, Shaghayegh
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p. 9033 - 9040
(2017/08/29)
-
- 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
-
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.
- Rostami, Amin,Tahmasbi, Bahman,Abedi, Fatemeh
-
p. 3689 - 3701
(2016/04/05)
-
- ERK INHIBITORS
-
The present invention provides a compound of Formula (I) or the pharmaceutically acceptable salts, esters, and prodrugs thereof, which are ERK2 inhibitors. The invention also provides a method of inhibiting ERK2 in a patient in need of such treatment comprising administering to said patient an effective amount of at least one compound of Formula (I). The invention also provides a method for treating cancer in a patient in need of such treatment, said method comprising administering to said patient an effective amount of at least one compound of Formula (I).
- -
-
Page/Page column 69-70
(2016/07/05)
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- Introduction of a New Ionic Liquid Catalyst for the Trimethylsilyl and Tetrahydropyranyl Protection of Alcohols
-
1,1'-Disulfo-[2,2'-bipyridine]-1,1'-hydrogen sulfate, BiPy(SO3H)2(HSO4)2, is prepared and identified as a new ionic liquid. This reagent was used for the promotion of the chemoselective trimethylsilyl and tetrahydropyranyl protection of alcohols. All reactions were performed under mild reaction conditions in high to excellent yields. Ease of the preparation of the heterogeneous catalyst, simplicity and easy work-up procedure, high reaction rates, and recyclability and reusability of the catalyst are the main advantages of this method.
- Shirini, Farhad,Abedini, Masoumeh,Mahmoodi, Nosratollah,Biglari, Mohammad,Safarpoor Nikoo Langrudi, Mohaddeseh
-
p. 1912 - 1921
(2015/12/12)
-
- Tetrahydropyranylation of alcohols in the presence of a slightly basic, heterogeneous titanium catalyst
-
4 ? molecular sieve modified with titanium (IV) is an efficient heterogeneous catalyst for the tetrahydropyranylation of alcohols under mild, slightly basic reaction conditions. The catalyst can be reused with good yield after a simple treatment with dichloromethane.
- Magyar, ágnes,Nagy, Balázs,Hell, Zoltán
-
p. 1876 - 1879
(2019/11/28)
-
- 3,5-Dinitrobenzoic acid catalyzed synthesis of 2,3-unsaturated O- and S-glycosides and tetrahydropyranylation of alcohols and phenols
-
A simple procedure for the synthesis of 2,3-unsaturated glycosides in acetonitrile and tetrahydropyranylation of alcohols and phenols in dichloromethane in the presence of 3,5-dinitrobenzoic acid is described. A variety of alcohols and thiols are reacted with glycals to give the desired products in high yields with high α-selectivity.
- Bodipati, Naganjaneyulu,Palla, Srinivasa Rao,Komera, Venkateshwarlu,Peddinti, Rama Krishna
-
supporting information
p. 6878 - 6881
(2015/02/02)
-
- Mild and efficient chemoselective tetrahydropyranylation of alcohols using bronsted acidic ionic liquid as catalyst under solvent-free conditions
-
A straightforward and efficient method for preparation of morpholinium bisulfate ([mroH]HSO4) as a novel acidic ionic liquid is reported. The application of this efficient and inexpensive acidic ionic liquid catalyst for tetrahydropyranylation of alcohols under mild and solvent-free conditions at room was investigated.
- Hajipour, Abdol R.,Nasresfahani, Zahra
-
experimental part
p. 1995 - 2006
(2012/06/04)
-
- Synthesis of sulfonic acid functionalized carbon catalyst from glycerol pitch and its application for tetrahydropyranyl protection/deprotection of alcohols and phenols
-
A novel carbon catalyst with -SO3H, -OH and -COOH functional groups was prepared from glycerol pitch by in situ partial carbonization and sulfonation with sulfuric acid. The activity of the catalyst was investigated through tetrahydropyranylation and dehydropyranylation of a wide variety of alcohols and phenols at room temperature by changing the solvent medium from dichloromethane to methanol. Excellent yields, short reaction times, easy and quick isolation of the products and reusability of the catalyst are the main attractions of this method. The novel carbon catalyst holds great potential in the green chemical processes.
- Prabhavathi Devi,Gangadhar,Siva Kumar,Shiva Shanker,Prasad,Sai Prasad
-
experimental part
p. 96 - 100
(2011/10/05)
-
- Tetrahydropyranylation of alcohols over modified zeolites
-
A catalytic amount of Moβ enables tetrahydropyranylation of various alcohols, phenols and naphthols under mild reaction conditions at room temperature in moderate to excellent yields within short reaction times is presented. The catalyst Moβ is reused without significant loss of activity. The product isolation is simple and environmentally benign.
- Narender,Suresh Kumar Reddy,Arun Kumar,Rohitha,Kulkarni
-
experimental part
p. 175 - 178
(2010/11/05)
-
- Carbon tetrabromide/sodium triphenylphosphine-m-sulfonate (TPPMS) as an efficient and easily recoverable catalyst for acetalization and tetrahydropyranylation reactions
-
A solid complex, conveniently prepared from carbon tetrabromide and sodium triphenylphos-phine-m-sulfonate (TPPMS), can be used as an easily recoverable catalyst for the selective acetalization of aldehydes and tetrahydropyranylation of alcohols. The catalyst can be recovered by simple pre-cipitation with ether and can be reused at least 7 times without loss of catalytic activity.
- Huo, Congde,Chan, Tak Hang
-
experimental part
p. 1933 - 1938
(2011/02/28)
-
- Copper nitrate/acetic acid as an efficient synergistic catalytic system for the chemoselective tetrahydropyranylation of alcohols and phenols
-
Tetrahydropyranylation of alcohols and phenols was accomplished successfully using copper nitrate and acetic acid as a synergistic catalyst at room temperature under solvent-free condition. Compared with other synergistic catalytic systems, copper nitrate/acetic acid proved to be the most efficient. Both alcohols (primary, secondary, tertiary, benzylic, cyclic, allyl, cinnamyl, and furyl) and phenols reacted smoothly in high yields. Graphical abstract: [Figure not available: see fulltext.]
- Wang, Min,Song, Zhi-Guo,Gong, Hong,Jiang, Heng
-
experimental part
p. 177 - 179
(2010/04/02)
-
- A highly efficient and ecofriendly procedure for tetrahydropyranylation of alcohols and phenols in the presence of in-situ generated I2 under heterogeneous and neutral conditions
-
Molecular iodine generated in situ from Fe(NO3) 3?9H2O/NaI acts as a highly efficient catalyst for tetrahydropyranylation of various alcohols and phenols with 3,4-dihydro-2H-pyran in almost quantitative yields. The reaction occurs rapidly in dichloromethane at room temperature, and use of toxic molecular iodine is avoided.
- Rostami, Amin,Rahmati, Sadegh,Khazaei, Ardeshir
-
experimental part
p. 663 - 667
(2010/05/18)
-
- Tetrahydropyranylation of alcohols under solvent-free conditions
-
A green, efficient, and large-scale method for tetrahydropyranylation of alcohols in the presence of a catalytic amount of pyridinium chloride at room temperature under solvent-free conditions is reported. Copyright Taylor & Francis Group, LLC.
- Hajipour, Abdol R.,Kargosha, Majid,Ruoho, Arnold E.
-
experimental part
p. 1084 - 1091
(2009/09/08)
-
- Mild and efficient deprotection of acetal-type protecting groups of hydroxyl functions by triethylsilyl triflate2,4,6-collidine combination
-
Deprotection of acetal-type protecting groups of hydroxyl functions has been studied in detail. The treatment of alcohol derivatives protected by acetal-type protecting groups with TESOTf2,4,6-collidine followed by H 20-treatment produces the corresponding hydroxyl compounds in good yields. The characteristic features of the method are very mild and chemoselective, and acid-labile functional groups can tolerate these conditions.
- Fujioka, Hiromichi,Kubo, Ozora,Okamoto, Kazuhisa,Senami, Kento,Okitsu, Takashi,Ohnaka, Takuya,Sawama, Yoshinari,Kita, Yasuyuki
-
experimental part
p. 1089 - 1103
(2010/10/20)
-
- A one-pot synthesis of (E)-disubstituted alkenes by a bimetallic [Rh-Pd]-catalyzed hydrosilylation/hiyama cross-coupling sequence
-
A bimetallic [Rh-Pd] catalyst was prepared by soaking into an iodide ionic gel an equimolar solution of [RhCl(PPh3)3] and Pd(OAc)2 in CH2Cl2. Its catalytic activity was evaluated by rhodium-catalyzed hydrosilylation (H), palladium-catalyzed Hiyama coupling (C), and in the one-pot hydrosilylation/Hiyama coupling sequence (H/C). It was found that the homogeneous combination [RhCl(PPh3) 3]/NaI was a superior system compared to the polyionic mono- and bimetallic rhodium catalysts in the hydrosilylation of terminal alkynes. Interestingly, the most effective catalyst in terms of stereo- and chemoselectivities was observed to be the bimetallic ionic gel [Rh-Pd] in the one-pot process leading to (E)-alkenes with good yields. The remarkable stereocontrol is ascribed to a beneficial Pd-catalyzed isomerization from the mixture of stereoisomeric vinylsilanes obtained in the initial hydrosilylation step into the more stable (E)-adduct. The [Rh-Pd] heterogeneous catalyst also showed a higher chemoselectivity than the homogeneous catalytic combination, and no detrimental formation of Sonogashira side product was observed due to an ionic-gel-mediated kinetic modulation. To illustrate its scope and limitations, the described one-pot bimetallic catalytic sequence was extended to functionalized terminal alkynes and various iodide substrates. Conjugated systems, such as hydroxycinnamaldehyde, dienes, and trienes, were synthesized in good overall yields. To avoid deactivation of the Rh species, N-heterocyclic iodides had to be added sequentially after completion of hydrosilylation.
- Thiot, Carine,Schmutz, Marc,Wagner, Alain,Mioskowski, Charles
-
p. 8971 - 8978
(2008/09/17)
-
- Parallel synthesis in an EOF-based micro reactor
-
We present herein a micro reactor set-up that enables parallel syntheses to be performed under electroosmotic flow conditions. The Royal Society of Chemistry.
- Wiles, Charlotte,Watts, Paul
-
p. 4928 - 4930
(2008/09/17)
-
- Generally applicable organocatalytic tetrahydropyranylation of hydroxy functionalities with very low catalyst loading
-
This paper presents the first acid-free, organocatalytic tetrahydropyran and 2-methoxypropene protection of alcohols, phenols, and other ROH derivatives utilizing privileged N,N′-bis[3,5-bis(trifluoromethyl)phenyl]thiourea and a polystyrene-bound analogue. The reactions are broadly applicably (also on preparative scale), in particular, to acid-sensitive substrates such as aldol products, hydroxy esters, acetals, silyl-protected alcohols, and cyanohydrins. The catalytic efficiency is truly remarkably with turnover numbers of 100,000 and turnover frequencies of up to 5700 h-1 at catalyst loadings down to 0.001 mol%. The computationally supported mechanistic interpretation emphasizes the hydrogen bond assisted heterolysis of the alcohol and concomitant preferential stabilization of the oxyanion hole in the transition state. Georg Thieme Verlag Stuttgart.
- Kotke, Mike,Schreiner, Peter R.
-
p. 779 - 790
(2008/01/03)
-
- Efficient and ecofriendly protocol for tetrahydropyranylation/ depyranylation of alcohols in the presence of tin(II) chloride dihydrate
-
A mild, efficient, and solvent-free protocol for tetrahydropyranylation of alcohols in the presence of a catalytic amount of SnCl2·2H2O is reported. Simple filtration of the reaction mixture through a short silica-gel pad gives the pure products in excellent yields. Depyranylation can also be achieved by adding methanol under similar reaction conditions. Copyright Taylor & Francis Group, LLC.
- Gogoi, Dipankoj,Baruah, Nabajyoti,Bez, Ghanashyam
-
p. 595 - 599
(2007/10/03)
-
- Silica triflate as a new, mild and efficient catalyst for tetrahydropyranylation of alcohols and deprotection of tetrahydropyranyl ethers
-
Silica triflate, a new stable derivative of silica gel, is easily prepared by the reaction of silica gel with trifluoromethanesulfonyl chloride. Silica triflate acts as a highly effective and reusable catalyst for tetrahydropyranylation of alcohols and deprotection of tetrahydropyranyl ethers under mild and completely heterogeneous reaction conditions.
- Shirini,Marjani,Nahzomi, H. Taherpour
-
p. 2235 - 2240
(2008/02/08)
-
- Tetrahydropyranylation of alcohols and phenols using the synergistic catalyst system, copper(II) chloride-acetic acid
-
Copper(II) chloride-acetic acid was found to be an efficient synergistic catalytic system for the tetraphydropyranylation of various alcohols and phenols in high yields at room temperature in short reaction times. Springer-Verlag 2007.
- Wang, Min,Song, Zhi-Guo,Jiang, Heng,Gong, Hong
-
p. 599 - 602
(2008/02/03)
-
- Preparation of functionalized anionic polymerization initiators
-
A process for preparing a functionalized polymerization initiator, the process comprising combining a functionalized styryl compound and an organolithium compound.
- -
-
Page/Page column 7
(2010/10/19)
-
- Efficient and convenient procedure for protection of hydroxyl groups to the THP, THF and TMS ethers and oxidation of these ethers to their aldehydes or ketones in [BPy]FeCl4 as a low cost room temperature ionic liquid
-
Alcohols were converted to the corresponding THP, THF or TMS ethers in high to excellent yields in 1-n-butylpyridinium chloroferrate media as a stable and low cost room temperature ionic liquid. In addition, oxidation of these ethers to their aldehydes or ketones without any overoxidation reactions in this ionic liquid was also performed.
- Khosropour, Ahmad R.,Khodaei, Mohammad M.,Ghaderi, Sattar
-
p. 326 - 330
(2007/10/03)
-
- Efficient trimethylsilylation and tetrahydropyranylation of alcohols in the presence of 1,3-dibromo-5,5-dimethylhydantoin
-
Chemoselective trimethylsilylation and tetrahydropyranylation of benzylic and primary and secondary aliphatic alcohols proceed efficiently in the presence of 1,3-dibromo-5,5-dimethylhydantoin (DBH) under mild and completely heterogeneous reaction conditio
- Shirini, Farhad,Zolfigol, Mohammad Ali,Paktinat, Maryam
-
p. 4252 - 4256
(2008/03/27)
-
- Tetrahydropyranylation and depyranylation of alcohols catalyzed by aqueous zinc tetrafluoroborate
-
Aqueous solution of zinc tetrafluoroborate as an effective catalyst for tetrahydropyranylation and depyranylation of alcohols has been described. Copyright Taylor & Francis, Inc.
- Islam, Samimul,Majee, Adinath,Khan
-
p. 1789 - 1793
(2007/10/03)
-
- Bronsted acidic ionic liquids: Fast, mild, and efficient catalysts for solvent-free tetrahydropyranylation of alcohols
-
Bronsted acidic ionic liquids as efficient and reusable catalysts for the protection of alcohols as tetrahydropyranyl (THP) ethers under solvent-free conditions at room temperature was investigated. Good to excellent yields were obtained at a faster rate over [BMIm][HSO4] or [BMIm][H2PO4]. Copyright Taylor & Francis, Inc.
- Duan, Zhiying,Gu, Yanlong,Deng, Youquan
-
p. 1939 - 1945
(2007/10/03)
-
- Use of allyl, 2-tetrahydrofuryl, and 2-tetrahydropyranyl ethers as useful C3-, C4-, and C5-carbon sources: Palladium-catalyzed allylation of aldehydes
-
Palladium-diethylzinc or palladium-triethylborane catalytically promotes self-allylation of 2-(allyloxy)tetrahydrofurans, 2-(allyloxy)tetrahydropyrans, and their hydroxy derivatives on the rings (ribose, glucose, mannose, deoxyribose, deoxyglucose). All the reactions proceed at room temperature and provide polyhydroxyl products, sharing a structural motif of a homoallyl alcohol, in good to excellent yields with high levels of stereoselectivity. Useful Crunit elongation, which makes the best use of an allyl ether as a protecting group and a nucleophilic allylation agent, is demonstrated. Mechanisms for the umpolung reaction (of an allyl ether into an allylic anion) and stereoselectivity associated with allylation of aldehydes are discussed.
- Shimizu, Masamichi,Kimura, Masanari,Tamaru, Yoshinao
-
p. 6629 - 6642
(2007/10/03)
-
- Convenient tetrahydropyranylation of alcohols and phenols by catalytic ferric sulfate hydrate (Fe2(SO4)3· xH2O)
-
Ferric sulfate hydrate (Fe2(SO4)3· xH2O) is found to be an efficient heterogeneous catalyst for the tetrahydropyranylation of alcohols and phenols at ambient or near ambient temperature. In addition, selective monotetrahydropyranylation of symmetrical diols is achieved under similar conditions. The deprotection of THP ether and direct transformation of THP ether to the corresponding acetate by Fe 2(SO4)3·xH2O is also studied. The simplicity of manipulation, mild conditions, reusable catalyst, good selectivity, and environment benign characters make this method a good alternative way for the THP protection of alcohols.
- Li, Lingjun,Zhu, Lizhi,Zhang, Xinying,Zhang, Guisheng,Qu, Guirong
-
p. 1120 - 1123
(2007/10/03)
-
- Simple and facile tetrahydropyranylation of alcohols by use of catalytic amounts of benzyltriphenylphosphonium tribromide
-
An efficient and mild system for protection of a variety of alcohols with 3,4-dihydro-2H-pyran (DHP) in the presence of catalytic amounts of benzyltriphenyl-phosphonium tribromide (BTPTB) (1) gives the corresponding tetrahydropyan ethers (ROTHP) in dichloromethane. The experimental procedure is simple, and the products are straightforwardly isolated in high to excellent yields. Copyright Taylor & Francis, Inc.
- Hajipour,Pourmousavi,Ruoho
-
p. 2889 - 2894
(2007/10/03)
-
- Silylation and tetrahydropyranylation of alcohols catalyzed by Al(HSO 4)3
-
Trimethylsilylation and tetrahydropyranylation of alcohols are efficiently catalyzed by Al(HSO4)3. All reactions were performed under mild and completely heterogeneous conditions in good-to-high yields.
- Shirini, Farhad,Zolfigol, Mohammad Ali,Abedini, Masoumeh
-
p. 1982 - 1985
(2007/10/03)
-
- Phosphorus pentoxide as an efficient catalyst for the tetrahydropyranylation of alcohols under solvent-free conditions
-
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.
- Eshghi, Hossein,Shafieyoon, Parvaneh
-
p. 2149 - 2152
(2007/10/03)
-
- Efficient tetrahydropyranylation of alcohols and detetrahydropyranylation reactions in the presence of catalytic amount of trichloroisocyanuric acid (TCCA) as a safe, cheap industrial chemical
-
Preparation and cleavage of THP ethers of different hydroxy functional groups are easily and efficiently performed in the presence of trichloroisocyanuric acid (TCCA) in the absence of solvent with high yields.
- Firouzabadi, Habib,Iranpoor, Nasser,Hazarkhani, Hassan
-
p. 3623 - 3630
(2007/10/03)
-
- A simple and efficient tetrahydropyranylation using N-bromosuccinamide
-
Tetrahydropyranylation of hydroxyl groups of alcohols and phenols has been achieved easily and efficiently using N-bromosuccinamide at room temperature.
- Das, Biswanath,Reddy, M. Ravinder,Ravindranath,Reddy, V. Saidi,Venkateshwarlu
-
p. 1711 - 1712
(2007/10/03)
-
- A Highly Efficient and Chemoselective Synthetic Protocol for Tetrahydropyranylation/Depyranylation of Alcohols and Phenols
-
Various alcohols and phenols can be converted efficiently to the corresponding tetrahydropyranyl (THP) ethers in good yields using catalytic amounts of bromodimethylsulfonium bromide (0.005-0.02 equivalent) at room temperature. On the other hand, various THP ethers can also be deprotected to the parent alcoholic or phenolic compounds in CH2Cl2/ MeOH (5:2) by employing 0.05 equivalent of the same catalyst. Some of the major advantages of this procedure are its mild conditions, that it is highly selective and efficient, high yielding, and cost-effective, that it needs no solvent and is compatible with the presence of other protecting groups. Furthermore, no brominations occur at a double or triple bond, at an allylic position or even at an aromatic ring. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
- Khan, Abu T.,Mondal, Ejabul,Borah, Ballav M.,Ghosh, Subrata
-
p. 4113 - 4117
(2007/10/03)
-
- InCl3 immobilized in ionic liquids: A novel and recyclable catalytic system for tetrahydropyranylation and furanylation of alcohols
-
A mild and highly efficient method has been developed for the protection of hydroxyl compounds as tetrahydropyranyl and furanyl ethers using a catalytic amount of indium trichloride immobilized in 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid under mild conditions. A wide range of functional and protecting groups such as THP, TBDMS, TBDPS, PMB, MOM ethers, acetonides, olefins and epoxides are compatible with ionic liquids. Monoprotection of diols has also been achieved using this novel procedure.
- Yadav, Jhillu Singh,Reddy, Basi V. Subba,Gnaneshwar, Dughani
-
p. 202 - 204
(2007/10/03)
-
- Bismuth triflate: An efficient catalyst for the formation and deprotection of tetrahydropyranyl ethers
-
The tetrahydropyranylation of alcohols under solvent-free conditions is efficiently catalyzed by bismuth triflate (0.1 mol %). The experimental procedure is simple and works well with a variety of alcohols and phenols. The catalyst is insensitive to air and small amounts of moisture, easy to handle and relatively nontoxic. The deprotection of THP ethers is also catalyzed by bismuth triflate (1.0 mol %). ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).
- Stephens, Jacqueline R.,Butler, Phillip L.,Clow, Curtis H.,Oswald, Matthew C.,Smith, Russell C.,Mohan, Ram S.
-
p. 3827 - 3831
(2007/10/03)
-
- Facile Tetrahydropyranylation of Alcohols and Phenols Using Anhydrous Calcium Chloride under Mild and Neutral Conditions
-
Treatment of 3,4-dihydro-2H-pyran with various alcohols and phenols in the presence of a catalytic amount of anhydrous calcium chloride in dichloromethane furnished tetrahydropyranyl ethers under almost neutral conditions.
- Bandgar, Babasaheb P.,Sadavarte, Vaibhav S.,Uppalla, Lavkumar S.,Patil, Suresh V.
-
p. 425 - 428
(2007/10/03)
-
- RuCl3, a mild and efficient catalyst for tetrahydropyranylation of alcohols and deprotection of tetrahydropyranyl ethers
-
Catalytic amount of anhydrous ruthenium trichloride in dry acetonitrile catalyzes efficiently tetrahydropyranylation of different types of alcohols to afford the corresponding tetrahydropyranyl ethers in high yields. Deprotection of tetrahydropyranyl ethers can also be achieved efficiently in the presence anhydrous ruthenium trichloride in wet acetonitrile.
- Kazemi,Kiasat,Ebrahimi
-
p. 2888 - 2889
(2007/10/03)
-
- A novel and efficient method for the synthesis of tetrahydropyranyl ethers catalyzed by Sc(OTf)3
-
Reaction of alcohols with dihydropyran in the presence of a catalytic amount of Sc(OTf)3 provides efficiently the corresponding tetrahydropyranyl ethers. After the reaction, the catalyst can be recovered quantitatively from the aqueous media and reused without loss of the activity.
- Watahiki, Tsutomu,Kikumoto, Hisashi,Matsuzaki, Masaya,Suzuki, Takeshi,Oriyama, Takeshi
-
p. 367 - 368
(2007/10/03)
-
- LiBF4: A mild and efficient catalyst for the tetrahydropyranylation of alcohols and their detetrahydropyranylation
-
Catalytic amount of lithium tetrafluoroborate in dry acetonitrile catalyzes an efficient tetrahydropyranylation of different types of alcohols to afford the corresponding tetrahydropyranyl ethers in high yields. Deprotection of tetrahydropyranyl ethers can also be achieved efficiently in the presence of lithium tetrafluoroborate in methanol. The chemoselectivity was observed in the protection of alcoholic function in the presence of phenolic function.
- Kazemi,Kiasat,Ebrahimi
-
p. 2483 - 2487
(2007/10/03)
-
- Microwave accelerated tetrahydropyranylation and detetrahydropyranylation of alcohols, phenols, and thiols catalyzed by hydrated zirconia
-
A solvent free and expeditious method for tetrahydropyranylation and detetrahydropyranylation of alcohols, phenols and thiols is described using hydrated zirconia and 3,4-dihydro-2H-pyran (DHP). A comparison of this microwave-accelerated reaction with conventional heating condition is also presented.
- Gajare, Anil S.,Sabde, Dhananjay P.,Shingare, Murlidhar S.,Wakharkar, Radhika D.
-
p. 1549 - 1555
(2007/10/03)
-
- An efficient zirconia catalyst for solvent free tetrahydropyranylation of alcohols and phenols
-
Alcohols and phenols are tetrahydropyranylated in the presence of sulfated zirconia catalyst in good to excellent yields under solvent free conditions.
- Reddy, Benjaram M.,Sreekanth, Pavani M.
-
p. 3561 - 3564
(2007/10/03)
-
- Simple, facile and highly selective tetrahydropyranylation of alcohols using silica chloride
-
A simple and efficient process for tetrahydropyranylation of alcohols has been developed by reacting with dihydropyran at room temperature in presence of catalytic amount of silica chloride. The process is highly selective for monoprotection of the hydroxyl groups of symmetric diols.
- Ravindranath,Ramesh,Das
-
p. 1777 - 1778
(2007/10/03)
-
- Simple protocol for synthesis and cleavage of tetrahydropyranyl ethers using FeSO4 as an inexpensive catalyst
-
Protection and deprotection of alcohols and phenols as tetrahydropyranyl ethers (THP ethers) using anhydrous FeSO4 under microwave irradiation without solvent is carried out.
- Bandgar, Babasaheb P.,Kasture, Suhas P.
-
p. 877 - 878
(2007/10/03)
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- Potassium dodecatangestocobaltate trihydrate (K5CoW12O40·3H2O): A mild and efficient catalyst for the tetrahydropyranylation of alcohols and their detetrahydropyranylation
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A simple, mild and effective method for tetrahydropyranylation of a variety of alcohols and cleavage of their tetrahydropyranyl ethers at ambient temperature in the presence of K5CoW12O40·3H2O as the catalyst with high turnovers is described.
- Habibi, Mohammad H.,Tangestaninejad, Shahram,Mohammadpoor-Baltork, Iraj,Mirkhani, Valiollah,Yadollahi, Bahram
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p. 2851 - 2853
(2007/10/03)
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- Protection of alcohols and phenols with dihydropyran and detetrahydropyranylation by ZrCl4
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Alcohols and Phenols are protected efficiently with dihydropyran(DHP) in the presence of catalytic amounts of zirconium tetrachloridein dichloromethane. Deprotection of THP-ethers is also afforded in a methanolic solution at room temperature.
- Rezai, Nasrin,Meybodi, Farhat Alsadat,Salehi, Peyman
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p. 1799 - 1805
(2007/10/03)
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- A mild and efficient method for tetrahydropyranylation/depyranylation of alcohols and phenols under neutral conditions
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Alcohols and phenols are tetrahydropyranylated rapidly in high yields in the presence of lithium bromide and dichloromethane at room temperature. Deprotection of these THP ethers can also be effected readily by mere change of the solvent to methanol and refluxing with excess lithium bromide. Due to neutral reaction conditions employed, the method is also compatible with compounds having acid sensitive functional groups.
- Reddy,Reddy,Bhanumathi,Rao
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p. 4323 - 4328
(2007/10/03)
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- Stannous chloride dihydrate: A new catalyst for the tetrahydropyranylation of alcohols
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Catalytic Stannous chloride dihydrate in polar aprotic solvents like chloroform efficiently catalyse the tetrahydropyranylation of alcohols in a short time under mild conditions.
- Joju Davis,Bhalerao,Vittal Rao
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p. 1679 - 1686
(2007/10/03)
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- Lithium tetrafluoroborate-in acetonitrile (LTAN) catalyzed Ferrier rearrangement - Facile synthesis of alkyl 2,3-unsaturated glycopyranosides?
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Treatment of 3,4-dihydro-2H-pyran 1 with various alcohols 2 - 10 furnished the tetrahydropyranyl ethers 11 - 19 in the presence of lithium tetrafluoroborate in acetonitrile (LTAN).
- Babu, B. Sobhana,Balasubramanian
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p. 1261 - 1262
(2007/10/03)
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