1831-57-8Relevant academic research and scientific papers
Acid-catalyzed transacetalization from glycol to pinacol acetals
Seeleib, Yvonne,Nemecek, Gregor,Pfaff, Dominik,Süveges, Bastian D.,Podlech, Joachim
, p. 2966 - 2973 (2014)
A one-pot transacetalization of glycol acetals, frequently used as protecting groups of the aldehyde function, into the more stable pinacol acetals is given. A clean transformation of aromatic and aliphatic substrates is possible with trifluoroacetic acid within 30 min at 0 °C. Glycol acetals derived from ketones (ketals) cannot be converted with this protocol. Deprotection of the pinacol acetals is possible with trifluoromethanesulfonic acid in the presence of water.
A Direct Method for the Efficient Synthesis of Benzylidene Acetal at Room Temperature
Reddy, Narra Rajashekar,Kumar, Rashmi,Baskaran, Sundarababu
supporting information, p. 1548 - 1552 (2019/01/09)
For the first time, a metal-free direct method has been developed for the efficient synthesis of benzylidene acetal at room temperature using Dowex 50WX8 as a solid acid catalyst and Cl3CCN as a novel water scavenger. At room temperature, a wide variety of aryl and α,β-unsaturated aldehydes react readily with functionalized 1,2- and 1,3-diols to furnish the corresponding acetals in very good yields. Labile functional groups, like N-Boc, N-Cbz, -OTBDMS, -OBn, -N3 and acetonide are found to be stable under the reaction conditions. The versatility of this method is further demonstrated with carbohydrate substrates and optically active diols.
Synthesis of pinacol acetals catalyzed by (2-carboxyphenyl)diphenylphosphonium bromide
Huang, Wenhua,Xu, Ning
supporting information, p. 2133 - 2138 (2017/10/31)
(2-Carboxyphenyl)diphenylphosphonium bromide that is readily prepared from commercial 2-(diphenylphosphino)benzoic acid and HBr is an efficient catalyst for the synthesis of pinacol acetals from a variety of aldehydes at room temperature.
Tropylium salts as efficient organic Lewis acid catalysts for acetalization and transacetalization reactions in batch and flow
Lyons,Crocker,Enders,Nguyen
supporting information, p. 3993 - 3996 (2017/09/08)
Acetalization reactions play significant roles in the synthetically important masking chemistry of carbonyl compounds. Herein we demonstrate for the first time that tropylium salts can act as organic Lewis acid catalysts to facilitate acetalization and transacetalization reactions of a wide range of aldehyde substrates. This metal-free method works efficiently in both batch and flow conditions, prompting further future applications of tropylium organocatalysts in green synthesis.
Radical Hydrodeiodination of Aryl, Alkenyl, Alkynyl, and Alkyl Iodides with an Alcoholate as Organic Chain Reductant through Electron Catalysis
Dewanji, Abhishek,Mück-Lichtenfeld, Christian,Studer, Armido
, p. 6749 - 6752 (2016/06/09)
A simple and efficient method for radical hydrodeiodination is reported. The novel approach uses electron catalysis. In situ generated Na-alcoholates are introduced as radical chain reducing reagents and reactions work with O2as cheap initiator. Hydrodeiodination works on aryl, alkenyl, alkynyl iodides and a tert-alkyl iodide also gets reduced applying the method. Albeit less general, the method is also applicable to the reduction of aryl bromides. The novel reagent is successfully used to conduct typical reductive radical cyclization reactions and mechanistic studies are reported.
Aromatic Nitration under Neutral Conditions Using Nitrogen Dioxide and Ozone as the Nitrating Agent. Application to Aromatic Acetals and Acylal
Suzuki, Hitomi,Yonezawa, Shuji,Mori, Tadashi
, p. 1535 - 1544 (2007/10/03)
Cyclic acetals derived from aromatic carbonyl compounds can be nitrated smoothly with nitrogen dioxide in ice-cooled dichloromethane or acetonitrile in the presence of ozone and magnesium oxide to give ortho- and para-nitro derivatives as the major product in good combined yields, the acetal ring as a protective group remaining almost intact.An acylal derived from benzaldehyde similarly undergoes nitration on the aromatic ring to give an isomeric mixture of three nitro compounds, in which the ortho and meta isomers predominate, while aromatic orthoesters are rapidly decomposed to give simply the parent esters.Ring nitration under neutral conditions has been interpreted in terms of a nonclassical mechanism, in which nitrogen trioxide is involved as the initial electrophile.
STABILITIES OF SOME 2-(PARA-SUBSTITUTED-PHENYL)-4,4,5,5-TETRAMETHYL-1,3-DIOXOLANES RELATIVE TO THEIR CONJUGATE DIOXOLENIUM IONS, RADICALS AND CARBANIONS AS DETERMINED BY THERMODYNAMICS FOR HYDRIDE AND ELECTRON TRANSFER IN SOLUTION
Arnett, Edward M.,Flowers, Robert A.,Meekhof, Alison E.,Pourjavadi, Ali,Walek, Stuart A.
, p. 663 - 671 (2007/10/02)
A calorimetric method is described for the determination of the hydride affinities, ΔHH-(R+) of seven dioxolenium ions from the title compounds and also tropylium, trityl and 9-phenylxanthylium cations by hydride transfer to the carb
ELECTRONIC EFFECT OF 1,3-DIOXACYCLANE SUBSTITUENTS IN NITROBENZALDEHYDE ACETALS
Ovchinnikov, V. V.,Evstaf'eva, Yu. G.,Latypova, V. Z.,Bogoveeva, G. A.,Cherkasov, R. A.
, p. 196 - 199 (2007/10/02)
The electronic effect of 1,3-dioxacyclane substituents in p- and m-nitrobenzaldehyde acetals was studied by IR spectroscopy and electrochemical reduction.In the investigated compounds the electron-withdrawing effect of the 1,3-dioxolane fragments is more
