1617-32-9Relevant academic research and scientific papers
A Facile Method for the Sulfenyllactonization of Alkenoic Acids Using Dimethyl Sulfoxide Activated by Oxalyl Chloride
Zhang, Ting,Dai, Yifeng,Cheng, Siwei,Liu, Yongguo,Yang, Shaoxiang,Sun, Baoguo,Tian, Hongyu
, p. 1380 - 1386 (2017)
A simple approach has been developed for the sulfenyllactonization of alkenoic acids using dimethyl sulfoxide activated with oxalyl chloride, in which methanesulfenyl chloride is proposed as the intermediate.
Stereochemical consequences in the deprotonation of enoates
Galatsis, Paul,Manwell, Jeffrey J.,Millan, Scott D.
, p. 5261 - 5264 (1996)
A cyclic transition structure for the deprotonation of enoates was proposed to rationalize the geometry of the deconjugated olefin and the substrate reactivity patterns.
THE BARRIER FOR 1,2 HYDROGEN SHIFT IN DIALKYL CARBENES
Stevens, Ian D. R.,Liu, Michael T. H.,Soundararajan, N.,Paike, N.
, p. 481 - 484 (1989)
The products from the thermolysis of 4-diazirinopentanoic acid (2) allow the estimate of an experimental value for the Ea = 1.1 +/- 1 kcal.mol-1 for the barrier height for 1,2 H shift in dialkyl carbenes.
Kinetics and Regioselectivity of Ring Opening of Substituted Cyclopropylmethyl Radicals
Beckwith, Athelstan L. J.,Bowry, Vincent W.
, p. 2681 - 2688 (1989)
Accurate analysis of the mixture of hydroxylamines 8 formed when suitable peroxides 4 undergo homolysis in the presence of the nitroxyl radical 1,1,3,3-tetramethylisoindolin-2-yloxy (T) has afforded rate constants for ring opening of the cyclopropylmethyl radicals 2a, 2c, 2dcis, 2dtrans, and 2e and cyclization of the but-3-enyl radicals 1a, 1c, and 1d.The presence of methyl substituents enhances the rates both of cyclization and of ring opening to give primary radicals.In the case of the trans-2-methylcyclopropyl radical, 2dtrans, this effect leads to preferential formation of the less thermodynamically stable possible product, 1d, below about 60 deg C.In general, the effects of substituents support the view that the transition structure for the cyclopropylmethyl-butenyl radical interconversion is dipolar.Combination of data from four sets of workers using three different kinetic techniques affords the following recommended Arrhenius equation for the cyclopropylmethyl radical clock reaction: log k1(2a) = 13.31 - 7.6/2.3RT.
Highly Regioselective 5-endo-tet Cyclization of 3,4-Epoxy Amines into 3-Hydroxypyrrolidines Catalyzed by La(OTf)3
Hoshino, Yoshihiko,Iwabuchi, Yoshiharu,Kuriyama, Yuse,Sasano, Yusuke,Uesugi, Shun-ichiro,Yamaichi, Aoto
supporting information, p. 1961 - 1965 (2021/01/04)
Highly regioselective intramolecular aminolysis of 3,4-epoxy amines has been achieved. Key features of this reaction are (1) chemoselective activation of epoxides in the presence of unprotected aliphatic amines in the same molecules by a La(OTf)3 catalyst and (2) excellent regioselectivity for anti-Baldwin 5-endo-tet cyclization. This reaction affords 3-hydroxy-2-alkylpyrrolidines stereospecifically in high yields. DFT calculations revealed that the regioselectivity might be attributed to distortion energies of epoxy amine substrates. The use of this reaction was demonstrated by the first enantioselective synthesis of an antispasmodic agent prifinium bromide.
Nickel-catalyzed electrocarboxylation of allylic halides with CO2
Wu, La-Xia,Deng, Fang-Jie,Wu, Lin,Wang, Huan,Chen, Tai-Jie,Guan, Ye-Bin,Lu, Jia-Xing
, p. 13137 - 13141 (2021/08/03)
Nickel-catalyzed regioselective electrocarboxylation of allylic halides with CO2at atmospheric pressure has been developed by adjusting reaction parameters, including catalyst, solvent, temperature and additive. β,γ-Unsaturated carboxylic acids were obtained in moderate to good yields and with high chain selectivity. This reaction shows tolerance to functional groups. In addition, cyclic voltammetry was performed to provide the possible mechanism of nickel-catalyzed CO2allylation.
Method for synthesizing (9Z, 12E)-9,12-tetradecadien-1-ol acetate
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Paragraph 0011; 0026-0028, (2020/06/16)
The invention belongs to the technical field of green pesticide synthesis, and discloses a novel method for synthesizing (9Z, 12E)-9,12-tetradecadien-1-ol acetate. According to the method, malonic acid and 9-bromo-1-nonyl alcohol are used as two starting raw materials. The method comprises the following steps: carrying out a Knoevenagel condensation reaction on malonic acid and propionaldehyde inthe presence of piperidine acetate to generate (E)-3-pentenoic acid, then carrying out lithium aluminum hydride reduction to obtain (E)-3-penten-1-ol, carrying out bromination reaction, and refluxingwith triphenylphosphine in acetonitrile to obtain (E)-3-pentenyltriphenylphosphine bromide; carrying out a PCC oxidation reaction on 9-bromo-1-nonanol to obtain 9-bromononanal, and then reacting the 9-bromononanal with potassium acetate to obtain 9-acetoxynonanal; and finally, carrying out a Wittig reaction on (E)-3-pentenyltriphenylphosphine bromide and 9-acetoxynonanal so as to obtain (9Z, 12E)-9,12-tetradecadien-1-ol acetate. An E-type double bond is constructed by utilizing the Knoevenagel condensation reaction of malonic acid and propionaldehyde, and the method has the advantages of mildreaction conditions, environmental friendliness, simple synthetic route and the like.
Probing the Mechanism of Photoaffinity Labeling by Dialkyldiazirines through Bioorthogonal Capture of Diazoalkanes
Am Ende, Christopher W.,Asare-Okai, Papa Nii,Fox, Joseph M.,Jemas, Andrew,O'brien, Jessica G. K.
supporting information, p. 9415 - 9420 (2020/12/21)
Dialkyldiazirines have emerged as reagents of choice for biological photoaffinity labeling studies. The mechanism of crosslinking has dramatic consequences for biological applications where instantaneous labeling is desirable, as carbene insertions display different chemoselectivity and are much faster than competing mechanisms involving diazo or ylide intermediates. Here, deuterium labeling and diazo compound trapping experiments are employed to demonstrate that both carbene and diazo mechanisms operate in the reactions of a dialkyldiazirine motif that is commonly utilized for biological applications. For the fraction of intermolecular labeling that does involve a carbene mechanism, direct insertion is not necessarily involved, as products derived from a carbonyl ylide are also observed. We demonstrate that a strained cycloalkyne can intercept diazo compound intermediates and serve as a bioorthogonal probe for studying the contribution of the diazonium mechanism of photoaffinity labeling on a model protein under aqueous conditions.
Regioselective Isomerization of Terminal Alkenes Catalyzed by a PC(sp3)Pincer Complex with a Hemilabile Pendant Arm
De-Botton, Sophie,Filippov, D.Sc. Oleg A.,Shubina, Elena S.,Belkova, Natalia V.,Gelman, Dmitri
, p. 5959 - 5965 (2020/10/15)
We describe an efficient protocol for the regioselective isomerization of terminal alkenes employing a previously described bifunctional Ir-based PC(sp3)complex (4) possessing a hemilabile sidearm. The isomerization, catalyzed by 4, results in a one-step shift of the double bond in good to excellent selectivity, and good yield. Our mechanistic studies revealed that the reaction is driven by the stepwise migratory insertion of Ir?H species into the terminal double bond/β-H elimination events. However, the selectivity of the reaction is controlled by dissociation of the hemilabile sidearm, which acts as a selector, favoring less sterically hindered substrates such as terminal alkenes; importantly, it prevents recombination and further isomerization of the internal ones.
Palladium-Catalyzed Amide-Directed Enantioselective Hydrocarbofunctionalization of Unactivated Alkenes Using a Chiral Monodentate Oxazoline Ligand
Wang, Hao,Bai, Zibo,Jiao, Tangqian,Deng, Zhiqiang,Tong, Huarong,He, Gang,Peng, Qian,Chen, Gong
supporting information, p. 3542 - 3546 (2018/03/21)
A Pd-catalyzed amide-directed enantioselective hydrocarbofunctionalization of unactivated alkenes with C-H nucleophiles has been developed using a chiral monodentate oxazoline (MOXin) ligand. Various indoles react at C3 position with aminoquinoline-coupled 3-alkenamides to give γ addition products in good to excellent yield and enantioselectivity. This study represents an important advance of the development of chiral monodentate oxazoline ligands, which have been underexplored for asymmetric catalysis.
