25988-32-3Relevant articles and documents
Reactions of a tungsten-germylyne complex with α,β-unsaturated ketones: Complete cleavage of the W/Ge bond and formation of two types of η3-germoxyallyl tungsten complexes
Fukuda, Tetsuya,Hashimoto, Hisako,Tobita, Hiromi
, p. 80 - 83 (2014)
Germylyne complex Cp(CO)2W/Ge{C(SiMe3)3} (1) reacted with two molecules of RC(O)CH=CH2 (R = Me, Et) to give η3-allyl complexes, in which an oxagermacyclopentene framework was bound to an η3-allyl ligand through an oxygen atom. In the reaction with α-Me-substituted MeC(O)C(Me)=CH2, 1 reacted with only one molecule of the substrate to give another type of η3- allyl complex, in which a five-membered oxagermacyclopentenyl ring was coordinated to the W center in an η3 fashion. Both reactions resulted in unprecedented complete cleavage of a W/Ge triple bond.
-
Jacob,P.,Brown,H.C.
, p. 7832 - 7833 (1976)
-
-
Bienvenue,A.,Duchatellier,B.
, p. 833 - 843 (1972)
-
Kinetics of the Unimolecular Elimination of Chlorobutanones in the Gas Phase
Chuhani, Gabriel,Hernandez A, Jose A.
, p. 4139 - 4141 (1981)
The gas-phase unimolecular elimination of 3-chloro-3-methyl-2-butanone has been investigated, in a static system and seasoned vessel, over the temperature range of 340-395 deg C and the pressure range of 60-190 torr.The reaction is homogeneous and unimolecular, follows a first-order rate law, and is invariable in the presence of cyclohexane, a radical-chain inhibitor.The products are isopropenyl methyl ketone and hydrogen chloride.The rate coefficients are given by the Arrhenius equation log k1 (s-1) = (12.56+/-0.31)-(190.8+/-3.7) kJ mol-1 (2.303RT)-1.When primary, secondary, and tertiary chlorobutanones are compared the presence of acetyl at the Cβ-Cl bond causes a significant rate enhancement due to the -M effect.However, if this substituent is at the Cα-Cl bond , deactivation in rate of elimination of these compounds is observed.The present work could well provide a general view on the effect of the acetyl substituent at the Cα-Cl and Cβ-Cl bonds in the molecular elimination of haloketones in the gas phase.
Cassis and Green Tea: Spontaneous Release of Natural Aroma Compounds from β-Alkylthioalkanones
B?ttig, Sarah,Bochet, Christian G.,Egger, Timothy,Flachsmann, Felix,Gey, Olga
, (2021/10/19)
In depth headspace analysis of the slow degradation of β-alkylthioalkanones in ambient air led to the discovery of a novel δ-cleavage pathway, by which β-mercaptoketones are released. Since β-mercaptoketones are potent natural aroma compounds occurring in many fruits, herbs and flowers, the discovery of an enzyme-independent molecular precursor for this class of high-impact molecules is of practical importance. Moreover, the formation of β-diketones and aldehydes by concomitant oxidation at the α-sulfur-position enhances the versatility of this class of aroma precursors. A mechanistic model is proposed which suggests that the oxidative degradation occurs through a novel Pummerer-type rearrangement of initially formed persulfoxides.
Hydroxyketones in the thiadiazine cycle formation
Pulatov, E. Kh.,Isobaev,Mavlonov
, p. 2475 - 2478 (2017/05/10)
Cyclocondensation of 1-hydroxyketones with thiosemicarbazide resulted in thiadiazines. Nitrate ester of 1-hydroxyketone reacted under similar conditions to give the corresponding thiosemicarbazone. In the case of bromoacetyl-substituted nitrate ester of 1-hydroxyketone, condensation proceeded via intramolecular reaction between the thiol and bromomethyl groups.
A structure/catalytic activity study of gold(i)-NHC complexes, as well as their recyclability and reusability, in the hydration of alkynes in aqueous medium
Fernández, Gabriela A.,Chopa, Alicia B.,Silbestri, Gustavo F.
, p. 1921 - 1929 (2016/04/05)
We conducted a structure/catalytic activity study of water-soluble gold(i) complexes-supporting sulfonated NHC ligands-in the hydration of alkynes in pure water or water nsp;:nsp;methanol (1nsp;:nsp;1), as well as their recyclability. Comparative studies were carried out with the addition of different silver salts. Our results indicate that the bulkier complex is the most effective and that the addition of methanol as co-solvent not only shortens reaction times but also stabilizes the less bulky complexes.