4840-68-0Relevant academic research and scientific papers
Pd(OAc)2-catalyzed orthogonal synthesis of 2-hydroxybenzoates and substituted cyclohexanones from acyclic unsaturated 1,3-carbonyl compounds
Miyagi, Toshinori,Okada, Sho,Tada, Naoya,Sugihara, Masahiro,Kagawa, Natsuko,Takabatake, Tetsuhiko,Toyota, Masahiro
, p. 1653 - 1657 (2019)
A Pd-catalyzed orthogonal synthesis of substituted 2-hydroxybenzoates and substituted cyclohexanones was developed for the first time. The substituted 2-hydroxybenzoates were obtained from acyclic unsaturated 1,3-carbonyl compounds using a combination of catalytic Pd(OAc)2 and Cu(OAc)2. On the other hand, the substituted cyclohexanones were produced from similar substrates via catalytic Pd(OAc)2 and hydrogen chloride. Each transformation was clean, easy to work up, provided the desired compounds in good purities, and did not require column chromatography purification.
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.
Kinetics and Equilibria of Keto-Enol Conversion in Aqueous Solution. Rate and Equilibrium Constants Determined from a Single Experiment
Groth-Andersen, Henrik,Soerensen, Poul E.
, p. 32 - 38 (2007/10/02)
The zero-order bromination of 2-carbethoxycyclohexanone in aqueous solution, followed spectrophotometrically at 267 nm, transforms near the end of the reaction quite suddenly into an opposing first-order process, representing a restoration of the perturbed keto-enol equilibrium.This is partly due to a (coincidental) overlap of the spectra for bromine and the substrate (enol) in the range 250-280 nm.Rate constants and the equilibrium constant for the keto-enol conversion can be determined (in principle) from a single kinetic experiment.The keto-enol conversion studied here is catalyzed only by bases, although a small component of catalysis by the hydronium ion is also found.Catalytic data for twelve bases, including water and the hydroxide ion, are correlated with pKA in a Broensted plot.Carboxylates form a linear correlation with a Broensted slope of β=0.67, in accordance with earlier observations.Phosphates exhibit moderately negative deviations, presumably due to electrostatic effects.Stronger bases show large negative deviations, undoubtedly relating to strong solvation of these ions.Kinetic experiments by stopped-flow in aqueous hydroxide provide a basis for determining the acidity constants for the substrate.
