15175-18-5Relevant articles and documents
CONFORMATIONAL EQUILIBRIA IN HALOCYCLOHEXANONES, AN NMR AND SOLVATION STUDY
Abraham, Raymond J.,Griffiths, Lee
, p. 575 - 584 (1981)
The conformational equilibrium in 2-chloro-cyclohexanone is measured in thirteen solvents from the 220 MHz 1H NMR spectrum, using the C2-H couplings and chemical shifts and the cis and trans-4-t-butyl-2-chlorocyclohexanones as refere
Efficient α-chlorination of carbonyl containing compounds under basic conditions using methyl chlorosulfate
Silva, Saúl,Maycock, Christopher D.
supporting information, p. 1233 - 1238 (2018/02/27)
An efficient method for the α-chlorination of ketones under basic conditions is described using methyl chlorosulfate. Its applicability for the chlorination of other functional groups has also been studied and it is equally useful for the synthesis of α-chloroesters and amides. Methyl chlorosulfate is described for the first time as a positive chlorine source. Some aldol reactions which occur during the chlorination of some substrates are also reported.
Direct conversion of alcohols to α-chloro aldehydes and α-chloro ketones
Jing, Yuanyuan,Daniliuc, Constantin G.,Studer, Armido
supporting information, p. 4932 - 4935 (2015/04/27)
Direct conversion of primary and secondary alcohols into the corresponding α-chloro aldehydes and α-chloro ketones using trichloroisocyanuric acid, serving both as stoichiometric oxidant and α-halogenating reagent, is reported. For primary alcohols, TEMPO has to be added as an oxidation catalyst, and for the transformation of secondary alcohols (TEMPO-free protocol), MeOH as an additive is essential to promote chlorination of the intermediary ketones.
Theoretical and experimental studies on the Baeyer-Villiger oxidation of ketones and the effect of α-halo substituents
Grein, Friedrich,Chen, Austin C.,Edwards, David,Crudden, Cathleen M.
, p. 861 - 872 (2007/10/03)
The Baeyer-Villiger reactions of acetone and 3-pentanone, including their fluorinated and chlorinated derivatives, with performic acid have been studied by ab initio and DFT calculations. Results are compared with experimental findings for the Baeyer-Villiger oxidation of aliphatic fluoro and chloroketones. According to theoretical results, the first transition state is rate-determining for all substrates even in the presence of acid catalyst. Although the introduction of acid into the reaction pathway leads to a dramatic decrease in the activation energy for the first transition state (TS), once entropy is included in the calculations, the enthalpic gain is lost. Of all substrates examined, pentanone reacts with performic acid via the lowest energy transition state. The second transition state is also lowest for pentanone, illustrating the accelerating effect of the additional alkyl group. Interestingly, there is only a small energetic difference in the transition states leading to migration of the fluorinated substituent versus the alkyl substituent in fluoropentanone and fluoroacetone. These differences match remarkably well with the experimentally obtained ratios of oxidation at the fluorinated and nonfluorinated carbons in a series of aliphatic ketones (calculated, 0.3 kcal/mol, observed, 0.5 kcal/mol), which are reported herein. The migration of the chlorinated substituent is significantly more difficult than that of the alkyl, with a difference in the second transition state of approximately 2.6 kcal/mol.
Lewis acid-mediated selective chlorinations of silyl enolate
Zhang, Yanhua,Shibatomi, Kazutaka,Yamamoto, Hisashi
, p. 15038 - 15039 (2007/10/03)
A new method involving efficient, widely applicable, and highly selective α-chlorination of simple silyl enolate with Lewis acid and an α,α-dichloro-1,3-dicarbonyl controller unit was reported. Diastereoselectivity and enantioselectivity of the reaction were investigated. High reactivity and selectivity were achieved by using α,α-dichlorinated malonic ester. Copyright
Catalytic cross-coupling of alkylzinc halides with α-chloroketones
Malosh, Chrysa F.,Ready, Joseph M.
, p. 10240 - 10241 (2007/10/03)
The cross-coupling of alkylzinc halides with α-chloroketones catalyzed by Cu(acac)2 is described. Using this method, primary and secondary alkyl groups are introduced adjacent to a ketone carbonyl under mild reaction conditions and in good yield. Cyclic, acyclic, aromatic, and aliphatic α-chloroketones are suitable substrates. Optically active α-chloroketones are converted to optically active products. The reaction was found to proceed stereospecifically with inversion of stereochemistry. The reaction is proposed to occur by direct substitution of the chloride with the alkyl group of an organocopper, -magnesium, or -zinc species. Copyright
α-chlorination of ketones using p-toluenesulfonyl chloride
Brummond, Kay M.,Gesenberg, Kirsten D.
, p. 2231 - 2234 (2007/10/03)
Treatment of a variety of ketones with lithium diisopropylamide followed by p-toluenesulfonyl chloride gives α-chloroketones in good yields. In addition, a polymer bound tosyl chloride reagent has also been shown to effect this transformation.
Axial/equatorial proportions for 2-substituted cyclohexanones
Basso,Kaiser,Rittner,Lambert
, p. 7865 - 7869 (2007/10/02)
Axial-equatorial conformational proportions have been measured for 2- substituted cyclohexanones in chloroform by the Eliel method for F, Cl, Br, I, MeO, MeS, Me2N, MeSe, and Me. For the first seven of these, at least five experimentally independent measurables were used and the resulting conformational preferences appear to be accurate to within 10%. Systematic errors degraded the results for MeSe and Me. For Me2N, the conformational preference also was measured for the first time at slow exchange in the low- temperature 13C spectrum in several solvents. In chloroform, steric and polar effects contribute to the conformational preferences, with steric effects dominant for large groups such as I and MeS.
