4300-02-1Relevant academic research and scientific papers
Ester enolate Claisen rearrangement using a polymer-supported silyl triflate
Hu, Yonghang,Porco Jr., John A.
, p. 3289 - 3292 (1999)
Polystyrene-diethylsilane resin (PS-DES) was treated with triflic acid to form a highly reactive polymer silyl triflate. The silyl triflate reacted with enolizable allylic esters in the presence of Et,N to afford resin-bound silyl ketene acetals, which undergo Ireland-Claisen rearrangement at elevated temperature to provide polymer silyl esters. Transesterification of the polymeric silyl esters with 5% H2SO4 in 1:1 MeOH/ClCH2CH2Cl (DCE) afforded methyl ester products.
Acid removal from crude oils by catalytic esterification naphthenic acid catalize by Mg/Al hydrotalcite
Redondo, Nicolás,Dieuzeide, Maria L.,Amadeo, Norma
, p. 82 - 87 (2020)
The presence of relatively high levels of naphthenic acids in crude oil may cause serious corrosion problem at temperature between 200 °C and 400 °C. One of the viable processes for decreasing acidity is the esterification of the present acids using an alcohol such as methanol. Therefore, the aim of this work is to develop a solid catalyst for the esterification reaction of 3-cyclopentylpropionic acid representative of the naphthenic acids. The esterification reaction is carried out at 80 °C, 3.5 kg/cm2 of pressure in a mechanically stirred batch reactor, using Mg-Al hydrotalcite (Mg/Al = 4) with different activation treatments as catalyst. These solids are characterized by N2 sorptometry and X ray diffraction. The higher concentration of Bronsted basic sites present in uncalcined hydrotalcite would explain the satisfactory performance obtained. TAN decreased 90percent by operating at a temperature as low as 80 °C after 60 min of reaction. The catalytic activity is evaluated at different reaction conditions such as, mass of catalyst, stirring speed and reaction temperature. A kinetic study for heterogeneous esterification of 3-cyclopentylpropionic acid with methanol was performed.
C?Boron Enolates Enable Palladium Catalyzed Carboboration of Internal 1,3-Enynes
Wang, Ziyong,Wu, Jason,Lamine, Walid,Li, Bo,Sotiropoulos, Jean-Marc,Chrostowska, Anna,Miqueu, Karinne,Liu, Shih-Yuan
supporting information, p. 21231 - 21236 (2021/09/02)
A new family of carbon-bound boron enolates, generated by a kinetically controlled halogen exchange between chlorocatecholborane and silylketene acetals, is described. These C?boron enolates are demonstrated to activate 1,3-enyne substrates in the presence of a Pd0/Senphos ligand complex, resulting in the first examples of a carboboration reaction of an alkyne with enolate-equivalent nucleophiles. Highly substituted dienyl boron building blocks are produced in excellent site-, regio-, and diastereoselectivity by the described catalytic cis-carboboration reaction.
Solar light-driven photocatalyzed alkylations. Chemistry on the window ledge
Protti, Stefano,Ravelli, Davide,Fagnoni, Maurizio,Albini, Angelo
supporting information; experimental part, p. 7351 - 7353 (2010/06/14)
Tetrabutylammonium decatungstate photocatalysis is effective for the C-H activation of alkanes, aldehydes, ethers and amides and the alkylation of alkenes occurs effectively by merely exposing the solution to the sun in a glass vessel on a window ledge (u
GAMMA LACTAMS AS PROSTAGLANDIN AGONISTS AND USE THEREOF
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Page 101, (2010/02/05)
1,2-substituted 5-pyrrolidinone compounds are provided, and methods of treatment and pharmaceutical composition that utilize or comprise one or more such compounds. Compounds of the invention are useful for a variety of therapies, including treating or preventing preterm labor, dysmenorrhea, asthma, hypertension, infertility or fertility disorder, undesired blood clotting, preeclampsia or eclampsia, an eosinophil disorder, sexual dysfunction, osteporosis and other destructive bone disease or disorder, renal dysfunction, an immune deficiency disorder, dry eye, ichthyosis, elevated intraocular pressure, sleep disorder, or gastric ulcer, inflammatory disorders and other diseases and disorders associated with the prostaglandin family of compounds.
Preparation of 1-phenylcyclohexa-2,5-diene-1-carboxylates and their use in free-radical mediated syntheses
Baguley, Paul A.,Jackson, Leon V.,Walton, John C.
, p. 304 - 309 (2007/10/03)
Synthetic routes to pure 1-phenylcyclohexa-2,5-diene-1-carboxylic acid and derived esters were developed. Esters containing appropriately unsaturated side chains generated the corresponding alkenyl radicals and hence gave good yields of 5-exo ring closure products in organotin-free reactions. Extrusion of phenyl radicals from the intermediate cyclohexadienyl type radicals was not observed, and this alternative β-scission did not compete under any conditions. Yields from alkylations of olefins in analogous intermolecular processes were, however, poor. As a spin-off from the research, it was found that 1-phenylcyclohexa-2,5-diene-1-carboxylic acid (6) was a useful source of hydroxyformyl (formate) radicals in organic solvents.
