25118-23-4Relevant academic research and scientific papers
α-Ethoxycarbonyl and α-methoxy substituted radical clocks
Newcomb, Martin,Filipkowski, Michelle A.,Johnson, Cathy C.
, p. 3643 - 3646 (1995)
Rate constants and Arrhenius functions for 5-exo cyclizations of the 1-(ethoxycarbonyl)-5-hexenyl radical, the 1-(ethoxycarbonyl)-1-methyl-5-hexenyl radical and the 1-methoxy-5-hexenyl radical were determined by indirect kinetic methods.
Method for preparing 6,8-dichloroethyl caprylate
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Paragraph 0045; 0046; 0048; 0052; 0054; 0058; 0060, (2021/03/13)
The invention provides a method for preparing 6,8-dichloroethyl caprylate. As shown in the following reaction formula, the method comprises the following reaction: performing oxidative esterificationon a compound 1 to obtain a compound 2, dehydrating to generate a compound 3, performing a Prins condensation reaction to obtain a compound 4, performing hydrolysis hydrogenation to obtain a compound5, and finally performing chlorination to obtain the 6,8-dichloroethyl caprylate. The method has the characteristics of easily available raw materials, simple process, high efficiency and environmental protection.
Cyclization Reactions of Oxyallyl Cation. A Method for Cyclopentane Ring Formation
Vulovic, Bojan,Trmcic, Milena,Matovic, Radomir,Saicic, Radomir N.
supporting information, p. 9618 - 9621 (2019/12/24)
Unsaturated oxyallyl cations with a suitably positioned alkene bond undergo 5-exo-cyclization with the formation of vinylcyclopentane derivatives. Alkyne analogues provide allenes. The reaction proceeds with a moderate to excellent level of stereoselectiv
First stereoselective total synthesis of Neocosmosin A: A facile approach
Dachavaram, Soma Shekar,Kalyankar, Kondbarao Balasaheb,Das, Saibal
supporting information, p. 5629 - 5631 (2014/12/11)
First stereoselective concise synthesis of Neocosmosin A, with in vitro binding affinity for human opioid and cannabinoid receptors, has been reported using readily available starting materials such as methylacetoacetate, cyclohexanone, and homoallyl alco
Treasures from the Free Radical Renaissance Period - Miscellaneous hexenyl radical kinetic data
Beckwith, Athelstan L. J.,Schiesser, Carl H.
body text, p. 1736 - 1743 (2011/05/03)
Rate constant data and Arrhenius parameters have been determined for a series of substituted hexenyl radicals of differing electronic and steric demand. Electron-withdrawing groups (CF3, CO2Et) directly attached to the radical centre slighly accelerate 5-exo ring-closure (k cis + ktrans ～ 2.1 × 105 s -1 at 25°) relative to donating groups (OMe; 1.6 × 10 5 s-1 at 25°). Sterically demanding groups (tert-Bu), as expected, slow the cyclization process (1 × 105 s -1). These observations are consistent with subtle changes in activation energy for 5-exo ring-closure. Interestingly, the nature of the solvent would appear to have a significant influence on this chemistry with the cis/trans stereoselectivity sometimes improved as the solvent polarity is increased. Except for the system containing the CF3 (electron-withdrawing) group which displays an increase in the cyclization/capture rate constant (kc/kH), a general decrease in the kc/kH ratio as solvent polarity is increased is noted; these changes have been speculated to arise mainly from changes in kH in the various solvents employed.
Cobalt-catalyzed reductive allylation of alkyl halides with allylic acetates or carbonates
Qian, Xin,Auffrant, Audrey,Felouat, Abdellah,Gosmini, Corinne
supporting information; experimental part, p. 10402 - 10405 (2011/12/03)
An efficient method for the direct allylation of alkyl halides catalyzed by simple cobalt(II) bromide has been developed. This reaction, using a variety of substituted allylic acetates or carbonates, provides the linear product as the major product. It displays broad substrate scope and good functional group tolerance. Copyright
Synthesis, antiviral activity, and conformational studies of a P3 aza-peptide analog of a potent macrocyclic tripeptide HCV protease inhibitor
Randolph, John T.,Zhang, Xiaolin,Huang, Peggy P.,Klein, Larry L.,Kurtz, Kevin A.,Konstantinidis, Alex K.,He, Wenping,Kati, Warren M.,Kempf, Dale J.
, p. 2745 - 2750 (2008/12/21)
BILN 2061 is a macrocyclic tripeptide inhibitor of hepatitis C virus NS3-4A protease that has shown efficacy in the clinic for treating patients infected with HCV. We have synthesized a P3 aza-peptide analog of a potent macrocyclic tripeptide inhibitor closely related to BILN 2061. This aza-derivative was found to be >2 orders of magnitude less active than the parent macrocycle in both isolated enzyme (HCV NS3-4A) and HCV subgenomic replicon assays. NMR studies of P3 aza-peptides revealed these compounds adopt a β-turn conformation stabilized by an intramolecular H-bonding interaction. Molecular models of these structures indicate a d-like configuration of the P3 aza-residue. Thus, the configurationally undefined nature at P3 in the aza-peptide allows the compound to adopt an H-bond stabilized conformation that is substantially different from that necessary for tight binding to the active site of HCV NS3 protease.
Ni-catalyzed cascade formation of C(sp3)-C(sp3) bonds by cyclization and cross-coupling reactions of iodoalkanes with alkyl zinc halides
Phapale, Vilas B.,Bunuel, Elena,Garcia-Iglesias, Miguel,Cardenas, Diego J.
, p. 8790 - 8795 (2008/09/20)
(Chemical Equation Presented) Two for the price of one: The formation of two C(sp3)-C(sp3) bonds can be achieved in a single operation by sequential cyclization and cross-coupling of alkyl zinc bromides with iodoalkanes containing an alkene group (see scheme). The reaction is catalyzed by [Ni(Py)4CI2] in the presence of tridentate nitrogen ligands, shows a high functional-group compatibility, and seems to follow a radical mechanism.
Stannyl radical-mediated cleavage of π-deficient heterocyclic sulfones. Synthesis of α-fluoro esters
Wnuk, Stanislaw F.,Rios, Jeannette M.,Khan, Jahanzeb,Hsu, Ya-Li
, p. 4169 - 4174 (2007/10/03)
Treatment of ethyl 2-(pyridin-2-ylsulfonyl)hexanoate with tributylstannane and azobis(2-methyl-2-propanitrile) (AIBN) in benzene at reflux for 36 h resulted in hydrogenolysis to give ethyl hexanoate (60%), whereas no reaction was observed after 48 h at reflux with ethyl 2-(phenylsulfonyl)-hexanoate. Ethyl 2-(pyrimidin-2-ylsulfonyl)hexanoate underwent quantitative hydrogenolysis within 1 h under these conditions. This represents a mild new methodology for removal of the synthetically useful sulfone moiety. Substitution of Bu3SnD for Bu3SnH gave access to α-deuterium-labeled esters. Treatment of the α-(pyrimidin-2-ylsulfonyl) enolates derived from several esters with Selectfluor gave high yields of the 2-fluoro-2-(pyrimidin-2-ylsulfonyl)alkanoates, which were smoothly desulfonylated [Bu3SnH (2 equiv)/AIBN/benzene/Δ] to give 2-fluoroalkanoates. "Catalytic" tin hydride, generated from tribuytltin chloride (0.15 equiv) and excess polymethylhydrosiloxane in the presence of potassium fluoride, also effected removal of the π-deficient α-(pyrimidin-2-ylsulfonyl) moiety from acid derivatives in high yields. Desulfonylation is suggested to proceed via alkoxy ketyl-type radicals and tin enolates.
Nickel-catalyzed preparations of functionalized organozincs
Vettel, Stephan,Vaupel, Andrea,Knochel, Paul
, p. 7473 - 7481 (2007/10/03)
The reaction of primary alkyl bromides or chlorides with diethylzinc in the presence of Ni(acac)2 (5 mol %) furnishes the corresponding alkylzinc halides (X = Br, Cl) via a halogen-zinc exchange reaction. The treatment of terminal alkenes with diethylzinc (neat, 25-60°C) in the presence of Ni(acac)2 as a catalyst (1-5 mol %) and 1,5-cyclooctadiene (COD) affords the corresponding dialkylzincs via a hydrozincation reaction. Whereas the conversion for simple alkenes bearing a remote functionality reaches 40 to 63%, the hydrozincation of allylic, homoallylic alcohols and allylic amines proceeds very efficiently (85-95% conversion). All the zinc organometallics obtained react with various electrophiles (allylic halides, enones, acid chlorides, alkynyl halides, ethyl propiolate) after transmetalation with CuCN·2LiCl. In the presence of the chiral catalyst 12, the dialkylzincs prepared add to aldehydes with high enantioselectivity.
