22612-62-0Relevant articles and documents
Pinacol Rearrangement and Direct Nucleophilic Substitution of Allylic Alcohols Promoted by Graphene Oxide and Graphene Oxide CO2H
Gómez-Martínez, Melania,Baeza, Alejandro,Alonso, Diego A.
, p. 1032 - 1039 (2017/03/27)
Graphene oxide (GO) and carboxylic acid functionalized GO (GO–CO2H) have been found to efficiently promote the heterogeneous and environmentally friendly pinacol rearrangement of 1,2-diols and the direct nucleophilic substitution of allylic alcohols. In general, high yields and regioselectivities are obtained in both reactions using 20 wt % of catalyst loading and mild reaction conditions.
An alternative reaction outcome in the gold-catalyzed rearrangement of 1-alkynyloxiranes
Gonzalez, Maria J.,Gonzalez, Jesus,Vicente, Ruben
, p. 6140 - 6143,4 (2020/09/16)
The gold(III)-catalyzed rearrangement of tetrasubstituted 1-alkynyloxiranes is described. This transformation led to a different reaction outcome with respect to related substrates previously studied. Thus, tertiary α-alkynylketones or alkynols can be selectively obtained. Moreover, gold(III) proved capable to catalyze the rearrangement of simple epoxides. These results indicate that gold(III) complexes act as oxophilic Lewis acids rather than π-acids in these transformations.
A one-pot cross-pinacol coupling/rearrangement procedure
Scheffler, Ulf,Mahrwald, Rainer
, p. 1970 - 1975,6 (2012/12/12)
A new catalytic retro-pinacol/cross-pinacol reaction, followed by subsequent rearrangement or deoxygenation of the intermediately formed vicinal diols, is described. This operationally simple one-pot protocol allows isolation of geminal α,α-diphenyl ketones or 1,1-diphenyl alkenes with high yields and selectivities. Copyright
Polymer-mediated pinacol rearrangements
Pavlik, Christopher,Morton, Martha D.,Smith, Michael B.
experimental part, p. 2191 - 2194 (2011/11/06)
Both poly(3,4-ethylenedioxythiophene) and poly(pyrrole) mediate a pinacol rearrangement of 1,2-diols. The yields of ketone or aldehyde products are comparable to those observed for treatment with mineral acids or Lewis acids. The advantage of this protocol is a two-phase reaction medium in hydrocarbon solvents that allows facile recovery of the products by simple filtration of the polymer and removal of solvents. Both the polymer and the hydrocarbon solvent may be recovered and used in subsequent reactions. Georg Thieme Verlag Stuttgart · New York.
Palladium-catalyzed intramolecular hydroalkylation of alkenyl- β-keto esters, α-aryl ketones, and alkyl ketones in the presence of Me 3SiCl or HCI
Han, Xiaoqing,Wang, Xiang,Pei, Tao,Widenhoefer, Ross A.
, p. 6333 - 6342 (2007/10/03)
Reaction of 3-butenyl β-keto esters or 3-butenyl α-aryl ketones with a catalytic amount of [PdCl2(CH3CN)2] (2) and a stoichiometric amount of Me3SiCl or Me3SiCl/ CuCl2 in dioxane at 25-70°C formed 2-substituted cyclohexanones in good yield with high regioselectivity. This protocol tolerated a number of ester and aryl groups and tolerated substitution at the allylic, enolic, and cis and trans terminal olefinic positions. In situ NMR experiments indicated that the chlorosilane was not directly involved in palladium-catalyzed hydroalkylation, but rather served as a source of HCl, which presumably catalyzes enolization of the ketone. Identification of HCl as the active promoter of palladium-catalyzed hydroalkylation led to the development of an effective protocol for the hydroalkylation of alkyl 3-butenyl ketones that employed sub-stoichiometric amounts of 2, HCl, and CuCl2 in a sealed tube at 70°C.
Palladium-catalyzed intramolecular hydroalkylation of unactivated olefins with dialkyl ketones
Wang, Xiang,Pei, Tao,Han, Xiaoqing,Widenhoefer, Ross A.
, p. 2699 - 2701 (2007/10/03)
(Matrix presented) Treatment of 3-butenyl heptyl ketone with substoichiometric amounts of PdCl2(CH3CN)2 (10 mol%), HCl (0.1 equiv), and CuCl2 (0.3 equiv) in dioxane at 70°C for 12 h in a sealed tube formed 2-hexylcyclohexanone in 77% isolated yield. A number of alkyl 3-butenyl ketones underwent hydroalkylation under these conditions to form 2-substituted cyclohexanones in moderate to good yield.
Substituent Effect of 1,4-Benzenedicarbonitriles as Sensitizers on the Photoinduced Electron Transfer Reactions in Alcohol
Suzuki, Masanori,Ikeno, Taketo,Osoda, Kazuhiko,Narasaka, Koichi,Suenobu, Tomoyoshi,Fukuzumi, Shunichi,Ishida, Akito
, p. 2269 - 2277 (2007/10/03)
In the photosensitized electron transfer reaction of 6,6-diphenyl-1,4-dioxaspiro[4.5]decane in methanol (MeOH), the quantum yield is increased by the use of 2-methylbenzene-1,4-dicarbonitrile (2-methyl-BDC) or 2,5-dirnethylbenzene-1,4-dicarbonitrile (2,5-
Preparation of 1,4-Dicyanobenzene Derivatives and the Substituent Effect of the Sensitizers on Photoinduced Electron-Transfer Reactions
Osoda, Kazuhiko,Pannecoucke, Xavier,Narasaka, Koichi
, p. 1119 - 1120 (2007/10/03)
Substituted 1,4-dicyanobenzenes are prepared as electron-accepting photosensitizers.The efficiency of some photosensitized reactions is influenced remarkably by the substituent(s) of 1,4-dicyanobenzene.By using mono or dimethylated dicyanobenzene, the rea
A convenient synthesis of 2,2-diphenyl-cyclohexanone and 6,6-diphenyl-2-cyclohexen-one
Bacque,Paris
, p. 2259 - 2272 (2007/10/02)
A short, convenient and large scale synthesis of 2,2-diphenyl-cyclohexanone and 6,6-diphenyl-2-cyclohexen-one using respectively the regioselective hydrogenolysis of 1,3-diketone (3) and the radical reduction of 3-bromo-2-enone (4) is reported.
Direct and Regiocontrolled Synthesis of α-Phenyl Ketones from Silyl Enol Ethers and Diphenyliodonium Fluoride
Chen, Kuanchiang,Koser, Gerald F.
, p. 5764 - 5767 (2007/10/02)
The efficiacy of diphenyliodonium fluoride (1, DIF) for the phenylation of silyl enol ethers was investigated.When the silyl enol ethers of cyclopentanone, 2-methylcyclopentanone, cyclohexanone, 2-methylcyclohexanone, acetophenone, 2-pentanone, diisopropyl ketone, and pinacolone were mixed with DIF in tetrahydrofuran, either α-phenyl or α,α-diphenyl ketones were produced and isolated in yields ranging from 20 to 88percent.That the regiochemistry of α-phenylation can be controlled by an appropriate choice of silyl enol ether was demonstrated with the kinetic and thermodynamic silyl enol ethers of 2-methylcyclohexanone, the thermodynamic silyl enol ether of 2-methylcyclopentanone, and the kinetic silyl enol ether of 2-pentanone. 3,3-Dimethyl-2-(silyloxy)-1-butene gave a dehydro dimer of pinacolone with DIF in addition to α-phenylpinacolone, thus suggesting that phenylations of silyl enol ethers with DIF may proceed via radical intermediates.
