944-19-4Relevant academic research and scientific papers
Site selectivity in the addition of ketoximes to activated allenes and alkynes; N- versus O-alkylation
Heaney, Frances,Kelly, Bronwyn M.,Bourke, Sharon,Rooney, Oliver,Cunningham, Desmond,McArdle, Patrick
, p. 143 - 148 (1999)
Reaction of ketoximes with methyl propiolate afforded geometrical isomers of the methyl 3-(hydroxyimino)-propanoates 4 and of the O-vinyl oximes 5 as well as the 2-isoxazoline 6. With dimethyl penta-2,3-diendioate 8c reaction progressed via an O-alkylatio
Development and Mechanistic Studies of the Iridium-Catalyzed C?H Alkenylation of Enamides with Vinyl Acetates: A Versatile Approach for Ketone Functionalization
Dong, Guangbin,Liu, Peng,Qi, Xiaotian,Zhou, Bo
supporting information, p. 20926 - 20934 (2021/08/18)
Ketone functionalization is a cornerstone of organic synthesis. Herein, we describe the development of an intermolecular C?H alkenylation of enamides with the feedstock chemical vinyl acetate to access diverse functionalized ketones. Enamides derived from various cyclic and acyclic ketones reacted efficiently, and a number of sensitive functional groups were tolerated. In this iridium-catalyzed transformation, two structurally and electronically similar alkenes—enamide and vinyl acetate—underwent selective cross-coupling through C?H activation. No reaction partner was used in large excess. The reaction is also pH- and redox-neutral with HOAc as the only stoichiometric by-product. Detailed experimental and computational studies revealed a reaction mechanism involving 1,2-Ir-C migratory insertion followed by syn-β-acetoxy elimination, which is different from that of previous vinyl acetate mediated C?H activation reactions. Finally, the alkenylation product can serve as a versatile intermediate to deliver a variety of structurally modified ketones.
As the carrier modified agent and a gelling agent cyclohexyl - mannitol double-ketal derivatives
-
Paragraph 0064; 0066, (2017/05/18)
Disclosure herein are cycylhexyl-mannitol diketal derivatives as vehicle modifiers and gelators having a formula of: wherein each R1 and R2 is independently alkyl, aryl, arylalkyl, alkaryl, or halogen; m is from 1 to 10; and n is from 1 to 10.
A General Access to Propargylic Ethers through Br?nsted Acid Catalyzed Alkynylation of Acetals and Ketals with Trifluoroborates
Baxter, Matthew,Bolshan, Yuri
supporting information, p. 13535 - 13538 (2015/09/22)
A general Br?nsted acid catalyzed methodology for the alkynylation of acetals and ketals with alkynyltrifluoroborate salts has been developed. The reaction proceeds rapidly to afford valuable synthetic building block propargylic ethers in good to excellent yields. Unlike Lewis acid catalyzed transformations of trifluoroborates, this approach does not proceed via unstable organodifluoroborane intermediate. As a result, the developed methodology features excellent functional group tolerance and good atom economy. Br?nsted acid catalyzed alkynylation of acetals and ketals is described. Alkynyltrifluoroborate salts react rapidly to afford propargylic ethers. Organodifluoroborane, which is a common intermediate in Lewis acid catalyzed reactions of trifluoroborates, has not been observed. The reaction exhibits generally high yields and excellent functional group tolerance.
Highly efficient acetalization of carbonyl compounds catalyzed by anilin-aldehyde resin salts
Tanemura, Kiyoshi,Suzuki, Tsuneo
supporting information, p. 797 - 799 (2015/06/22)
A mild procedures for the syntheses of ethylene acetals and dimethyl acetals from the corresponding aldehydes and ketones catalyzed by 1mol% of anilinealdehyde resin salts are described. This method is also useful for the synthesis of dimethyl acetals of diaryl ketones.
Anodic cleavage of several ketone N-phenylsemicarbazones into methyl N-phenylcarbamate and the corresponding dimethyl acetals
Nishikawa, Shinnosuke,Yamamori, Haruki,Ohashi, Kousuke,Okimoto, Mitsuhiro,Hoshi, Masayuki,Yoshida, Takashi
, p. 1766 - 1771 (2013/05/21)
Several ketone N-phenylsemicarbazones were electrooxidized in the presence of potassium iodide and a base using methanol as the solvent to give nearly commensurate amounts of methyl N-phenylcarbamate and the corresponding dimethyl acetals. Continuous evolution of gaseous nitrogen was observed from the anolyte during the electrooxidation. The reactions were carried out under very mild reaction conditions and are presumed to proceed through a four-electron oxidation process, in which the iodide ion plays an important role as an electron carrier.
Mesoporous aluminosilicate-catalyzed allylation of carbonyl compounds and acetals
Ito, Suguru,Hayashi, Akira,Komai, Hirotomo,Yamaguchi, Hitoshi,Kubota, Yoshihiro,Asami, Masatoshi
supporting information; experimental part, p. 2081 - 2089 (2011/04/19)
A mesoporous aluminosilicate (Al-MCM-41) was found to be an effective heterogeneous catalyst for the reaction of both carbonyl compounds and acetals with allylsilanes to afford the corresponding homoallyl silyl ethers and homoallyl alkyl ethers, respectively. Both the mesoporous structure and the presence of aluminum moiety were indispensable for the high catalytic activity of Al-MCM-41. Moreover, Al-MCM-41 could catalyze the reaction of acetals chemoselectively in the presence of the corresponding carbonyl compounds. The solid acid catalyst Al-MCM-41 could be recovered easily by filtration and could be reused three times without a significant loss of catalytic activity.
o-benzenedisulfonimide as reusable bronsted acid catalyst for acid-catalyzed organic reactions
Barbero, Margherita,Cadamuro, Silvano,Dughera, Stefano,Venturello, Paolo
, p. 1379 - 1388 (2008/12/21)
Acid-catalyzed organic reactions, such as etherification, esterification, acetal synthesis, cleavage, and interconversion, and pinacol rearrangement were carried out in the presence of catalytic amounts of o-benzenedisulfonimide as Bronsted acid catalyst; the conditions were mild and selective. The catalyst was easily recovered and purified, ready to be used in further reactions, with economic and ecological advantages. Georg Thieme Verlag Stuttgart.
Electrostatic effects on the reactions of cyclohexanone oxocarbenium ions
Baghdasarian, Glen,Woerpel
, p. 6851 - 6858 (2007/10/03)
Nucleophilic substitution reactions of 4-substituted cyclohexanone acetals display different selectivities depending upon the electronic nature of the substituent. Alkyl groups favor equatorial positions in the oxocarbenium ions, but alkoxy groups prefer
Photochemical generation of six- and five-membered cyclic vinyl cations
Slegt, Micha,Gronheid, Roel,Van Vlugt, Dennis Der,Ochiai, Masahito,Okuyama, Tadashi,Zuilhof, Han,Overkleeft, Hermen S.,Lodder, Gerrit
, p. 2227 - 2235 (2007/10/03)
The photochemical solvolyses of 4-tert-butylcyclohex-1-enyl(phenyl)iodonium tetrafluoroborate (1) and cyclopent-1-enyl(phenyl)iodonium tetrafluoroborate (2) in methanol yield vinylic ethers and vinylic cycloalkenyliodobenzenes and cycloalkenylbenzene, which are the trapping products of the geometrically destabilized C6-ring and C5-ring vinyl cation with the solvent and with the leaving group iodobenzene. Iodonium salt 2 also yields an allylic ether and allylic cyclopentenyliodobenzenes and cyclopentenyl-benzene, which are the trapping products of the C5-ring allylic cation produced from the C5-ring vinyl cation by a hydride shift in a typical carbocationic rearrangement.
