- Highly effective acetalization of aldehydes and ketones with methanol on siliceous mesoporous material
-
Aromatic and linear aldehydes as well as cyclohexanone could be converted to the corresponding dimethylacetals in yields of ca. 90-100% at ambient or refluxing temperature in the titled reaction.
- Tanaka, Yasuhiro,Sawamura, Naoki,Iwamoto, Masakazu
-
-
Read Online
- An efficient and versatile procedure for the synthesis of acetals from aldehydes and ketones catalyzed by lithium tetrafluoroborate
-
Acetals are obtained in good to excellent yields by treatment of aldehydes and ketones with trialkyl orthoformate and the corresponding alcohol in the presence of a catalytic amount of lithium tetrafluoroborate. Due to the mild reaction conditions, this method is compatible with acid-sensitive substrates.
- Hamada, Nao,Kazahaya, Kiyoshi,Shimizu, Hisashi,Sato, Tsuneo
-
-
Read Online
- Novel and facile selective reduction of carboxylic acid with a samarium diiodide-lanthanide triflate-methanol-base system
-
The facile selective reduction of carboxylic acids in the presence of an aldehyde or that bearing a formyl group proceeded smoothly with a samarium diiodide-lanthanide triflate-methanol-base system at room temperature to give the corresponding alcohols in good to almost quantitative yield.
- Kamochi, Yasuko,Kudo, Tadahiro
-
-
Read Online
- Formation of Acetals and Ketals from Carbonyl Compounds: A New and Highly Efficient Method Inspired by Cationic Palladium
-
The development of a new, highly efficient, and simple method for masking carbonyl groups as acetals and ketals is described. This methodology relies on the nature of the palladium catalyst to direct the acetalization/ketalization reaction. This new protocol is mild and proceed with a very low catalyst loading at ambient temperatures. The method has been extended to a wide variety of different carbonyl compounds with various steric encumbrances to form the corresponding acetals and ketals in excellent yields.
- Green, Shawn D.,Kindoll, Tyler,Lazaro-Martinez, Brenda,Mensah, Enoch A.,West, Jesse
-
-
Read Online
- A recyclable fluorous hydrazine-1,2-bis(carbothioate) with NCS as efficient catalysts for acetalization of aldehydes
-
A fluorous hydrazine-carbothioate organocatalyst was prepared. Together with NCS, the catalyst showed a good activity in acetalization of aldehydes and alcohols. It could be recovered from the reaction mixture by fluorous solid-phase extraction (F-SPE) with excellent purity for direct reuse.
- Zhu, Yi-Wei,Yi, Wen-Bin,Cai, Chun
-
-
Read Online
- Zinc chloride as an efficient catalyst for chemoselective dimethyl acetalization
-
Commercially available anhydrous zinc chloride has been found to be a highly efficient catalyst for dimethyl acetalization in high yields by treatment of aldehydes and ketones with trimethyl orthoformate in methanol-cyclohexane at reflux temperature. Copyright Taylor & Francis Group, LLC.
- Roy, Anupam,Rahman, Matiur,Das, Sudarshan,Kundu, Dhiman,Kundu, Shrishnu Kumar,Majee, Adinath,Hajra, Alakananda
-
-
Read Online
- Transformations of peroxide olefin ozonolysis products in methanol in the presence of water
-
Transformations of peroxide products of ozonolysis of various olefins with different degrees of substitution at the double bond by the action of hydroxylamine and semicarbazide hydrochloride in methanol in the presence of water as co-solvent were studied.
- Ishmuratov,Legostaeva,Garifullina,Botsman,Muslukhov,Tolstikov
-
-
Read Online
- Photo-organocatalytic synthesis of acetals from aldehydes
-
A mild and green photo-organocatalytic protocol for the highly efficient acetalization of aldehydes has been developed. Utilizing thioxanthenone as the photocatalyst and inexpensive household lamps as the light source, a variety of aromatic and aliphatic aldehydes have been converted into acyclic and cyclic acetals in high yields. The reaction mechanism was extensively studied.
- Nikitas, Nikolaos F.,Triandafillidi, Ierasia,Kokotos, Christoforos G.
-
-
Read Online
- One-pot Synthesis of Acetals by Tandem Hydroformylation-acetalization of Olefins Using Heterogeneous Supported Catalysts
-
Abstract: A green route for one?pot synthesis of acetals by tandem hydroformylation?acetalization of olefins using supported Rh?based?catalysts was developed. Experimental results demonstrated that suitable Rh loading (1 wt%) with appropriate reaction temperature (120?°C) and reaction time (8?h) were favorable for the formation of acetals, and a high acetals selectivity of 94.6% was achieved. More importantly, the selectivity to valuable linear products was enhanced in this tandem catalysis. Based on the catalytic mechanism study, highly dispersed RhOx nanoparticles and abundant acid sites on the supports were responsible for the hydroformylation and acetalization, respectively. Graphical abstract: One-pot synthesis of acetals directly from olefins with high selectivity was achieved over heterogeneous bifunctional catalysts via tandem hydroformylation-acetalization. [Figure not available: see fulltext.]
- Li, Xiao,Qin, Tingting,Li, Liusha,Wu, Bo,Lin, Tiejun,Zhong, Liangshu
-
-
Read Online
- SO3H-functionalized silica for acetalization of carbonyl compounds with methanol and tetrahydropyranylation of alcohols
-
Sulfonic acid group-functionalized amorphous silica acts as a highly effective and reusable catalyst for acetalization of various carbonyl compounds with methanol and tetrahydropyranylation of alcohols.
- Shimizu, Ken-Ichi,Hayashi, Eidai,Hatamachi, Tsuyoshi,Kodama, Tatsuya,Kitayama, Yoshie
-
-
Read Online
- NCS with thiourea as highly efficient catalysts for acetalization of aldehydes
-
NCS/thiourea-mediated acetalization of aldehydes and alcohols has rapidly provided acetals in almost quantitative yields.
- Mei,Bentley,Du
-
-
Read Online
- Photochemical synthesis of acetals utilizing Schreiner's thiourea as the catalyst
-
Acetalization of aldehydes is an area of great importance in Organic Chemistry for both synthetic and biological puproses. Herein, we report a mild, inexpensive and green photochemical protocol, where Schreiner's thiourea (N,N′-bis[3,5-bis(trifluoromethyl)-phenyl]-thiourea) is utilized as the catalyst and cheap household lamps as the light source. A variety of aromatic and aliphatic aldehydes were converted into acetals in good to high yields (23 examples, 36-96% yield) and an example of the synthesis of a cyclic acetal is provided. The reaction mechanism was also studied.
- Kokotos, Christoforos G.,Nikitas, Nikolaos F.,Spiliopoulou, Nikoleta
-
supporting information
p. 3539 - 3545
(2020/06/25)
-
- House bulb light-induced photochemical acetalization of carbonyl compounds catalyzed by Eosin Y
-
We have systematically studied the reactions of acetalization and found that high reaction efficiency can be achieved using cheap and readily available organic Eosin Y as catalyst. The reaction proceeds smoothly under house bulbs and shows excellent functional group tolerance. The substrates of the reaction system are compatible with aromatic aldehydes, aliphatic aldehydes, aromatic ketones, and cyclic ketones with high yields.
- Zhou, Quan,Jia, Tao,Li, Xiao-Xuan,Zhou, Lin,Li, Chang-Jiang,Feng, Yi-Si
-
supporting information
p. 1068 - 1075
(2018/05/23)
-
- Access to Wieland-Miescher Diketone-Derived Building Blocks by Stereoselective Construction of the C-9 Quaternary Carbon Center Using the Mukaiyama Aldol Reaction
-
The Mukaiyama aldol reaction has been used to efficiently install a lateral chain at the C-9 position of the Wieland-Miescher ketone derivative 3 within two steps, representing a shortcut compared to that of the classical sequences. The treatment of the silylated enol ether 8 with a wide range of acetals in the presence of tin tetrachloride led to a the diastereoselective construction of the C-9 quaternary center of 33 new building blocks derived from the Wieland-Miescher ketone derivative 3.
- Schiavo, Lucie,Lebedel, Ludivine,Massé, Paul,Choppin, Sabine,Hanquet, Gilles
-
p. 6247 - 6258
(2018/06/22)
-
- Highly atom-efficient and chemoselective reduction of ketones in the presence of aldehydes using heterogeneous catalysts
-
The first demonstration of a 100% atom-efficient selective reduction of less reactive ketones over aldehydes using heterogeneous catalysts is reported. Extremely high selectivities for intra- and intermolecular reductions of ketones over aldehydes were achieved. This system was also applicable to a column reactor, leading to a gram-scale synthesis.
- Takahashi, Yusuke,Mitsudome, Takato,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
-
supporting information
p. 2695 - 2698
(2013/10/08)
-
- A facile procedure for acetalization of aldehydes and ketones catalyzed by cerium(III) trifluoromethanesulfonate
-
Aldehydes and ketones are readily protected in the presence of trialkyl orthoformate and a catalytic amount of cerium(III) trifluoromethanesulfonate under mild conditions to give the corresponding acetals in good to excellent yields. Due to the mild reaction conditions, this method is compatible with acid-sensitive substrates. Copyright
- Ono, Fumiaki,Inatomi, Yoshiko,Tada, Yuusuke,Mori, Masaki,Sato, Tsuneo
-
experimental part
p. 96 - 97
(2009/11/30)
-
- Ruthenium(III) chloride-catalyzed chemoselective synthesis of acetals from aldehydes
-
A mild and chemoselective acetalization procedure for the protection of various aldehydes in the presence of ketones is described.
- De, Surya K.,Gibbs, Richard A.
-
p. 8141 - 8144
(2007/10/03)
-
- BROMINATION OF DIMETHYLACETALS WITH Br2-CHLOROTRIMETHYLSILANE-NaBr
-
α-Bromodimethylacetals are obtained in excellent yields by treating dimethylacetals with Br2-NaBr-chlorotrimethylsilane in CH3OH/CH3CN (2:1). The method is suitable for large scale preparation.
- Bellesia, Franco,Boni, Monica,Ghelfi, Franco,Pagnoni, Ugo Maria
-
p. 629 - 632
(2007/10/02)
-
- Kinetische Untersuchungen zur Methanolyse von Acetalen
-
It has been shown that the acid-catalyzed methanolysis of the diethylacetales RCH(OEt)2 of acetaldehyde (R=CH3), propionaldehyde (R = C2H5), butyraldehyde (R = C3H7) and caprylaldehyde (R = C7H15) at temperatures between 283 and 318 K proceeds as a consecutive reaction involving a reversible second step.The pseudo first order rate constants of the three reaction steps, their activation parameters and equilibrium constants were estimated by measuring the concentration-time-curves of starting product, intermediate and final product and using a large excess of methanol.There is a linear dependence be tween rate constants of methanolysis and concentration of the catalyst.
- Claus, P.,Berndt, T.,Scherzer, K.
-
p. 1205 - 1216
(2007/10/02)
-
- Anodic α-Methoxylation of Aliphatic Saturated Ethers
-
The anodic oxidation of aliphatic saturated ethers carried out in a mixed solvent of methanol and acetic acid gave α-methoxylated ethers in much better yields than those obtained by using only methanol as a solvent.
- Shono, Tatsuya,Matsumura, Yoshihiro,Onomura, Osamu,Yamada, Yasufu
-
p. 1099 - 1100
(2007/10/02)
-