1552-67-6Relevant academic research and scientific papers
Synergistic Relay Reactions To Achieve Redox-Neutral α-Alkylations of Olefinic Alcohols with Ruthenium(II) Catalysis
Kan, Jian,Li, Chao-Jun,Li, Chen-Chen,Li, Jianbin,Lv, Leiyang,Qiu, Zihang
supporting information, p. 4544 - 4549 (2020/02/04)
Herein, we report a ruthenium-catalyzed redox-neutral α-alkylation of unsaturated alcohols based on a synergistic relay process involving olefin isomerization (chain walking) and umpolung hydrazone addition, which takes advantage of the interaction between the two rather inefficient individual reaction steps to enable an efficient overall process. This transformation shows the compatibility of hydrazone-type “carbanions” and active protons in a one-pot reaction, and at the same time achieves the first Grignard-type nucleophilic addition using olefinic alcohols as latent carbonyl groups, providing a higher yield of the corresponding secondary alcohol than the classical hydrazone addition to aldehydes does. A broad scope of unsaturated alcohols and hydrazones, including some complex structures, can be successfully employed in this reaction, which shows the versatility of this approach and its suitability as an alternative, efficient means for the generation of secondary and tertiary alcohols.
Total synthesis of micromide: A marine natural product
Han, Jianrong,Lian, Jingtang,Tian, Xia,Zhou, Shengwei,Zhen, Xiaoli,Liu, Shouxin
, p. 7232 - 7238 (2015/02/19)
This paper describes an efficient procedure for the synthesis of micromide, a natural product that shows anti-solid-tumor activity. Our strategy involved the synthesis of N-nosyl-protected amino acids and their N-methylation with iodo-methane. The hindered oligopeptides containing N-methyl amino acids were synthesized in excellent yields and high purities.[ampi]]
Discovery of heterocyclic nonacetamide synaptic vesicle protein 2A (SV2A) ligands with single-digit nanomolar potency: Opening avenues towards the first SV2A positron emission tomography (PET) ligands
Mercier, Joel,Archen, Laurence,Bollu, Veronique,Carre, Stephane,Evrard, Yves,Jnoff, Eric,Kenda, Benoit,Lallemand, Benedicte,Michel, Philippe,Montel, Florian,Moureau, Florence,Price, Nathalie,Quesnel, Yannick,Sauvage, Xavier,Valade, Anne,Provins, Laurent
, p. 693 - 698 (2014/05/06)
The role of the synaptic vesicle protein 2A (SV2A) protein, target of the antiepileptic drug levetiracetam, is still mostly unknown. Considering its potential to provide in vivo functional insights into the role of SV2A in epileptic patients, the development of an SV2A positron emission tomography (PET) tracer has been undertaken. Using a 3D pharmacophore model based on close analogues of levetiracetam, we report the rationale design of three heterocyclic non-acetamide lead compounds, UCB-A, UCB-H and UCB-J, the first single-digit nanomolar SV2A ligands with suitable properties for development as PET tracers. Avenues towards imaging... of synaptic vesicle protein 2A (SV2A) in vivo were opened after the rationale discovery of the first non-acetamide SV2A ligands, displaying single-digit nanomolar potency, using a 3D pharmacophore model. An extensive profiling of the most potent compounds allowed the identification of three leads (see figure) as potential candidates for positron emission tomography (PET) ligand development.
Method for regio- and stereoselective synthesis of (E)-Β,γ- unsaturated acids from aldehydes under solvent-free conditions
Zhang, Shi-Jie,Hu, Wei-Xiao
experimental part, p. 3093 - 3100 (2010/12/19)
Synthesis of (E)-β,-γunsaturated acids from aldehydes with malonic acid has been explored under solvent-free conditions. The modified Knoevenagel condensation reaction with N-methyl morpholine (NMM) as catalyst exhibits highly β,-γ regioselectivity and exclusively E-stereoselectivity. A mechanism accounting for both regio- and stereoselectivity has been proposed and preliminarily studied. Copyright Taylor & Francis Group, LLC.
Unusual temperature dependence of salt effects for "on water" Wittig reaction: Hydrophobicity at the interface
Tiwari, Shraeddha,Kumar, Anil
scheme or table, p. 4445 - 4447 (2009/05/06)
An unusual variation with temperature of the salt effects in aqueous Wittig reaction is observed, suggesting that hydrophobic acceleration of reactions comprising "on water" reactants is fundamentally different from that for reactions with small non-polar solutes. The Royal Society of Chemistry.
Free-radical-mediated Carbonylative Cyclization of Alk-4-enyl Halides Leading to Cyclopentanone
Ryu, Ilhyong,Kusano, Kazuya,Hasegawa, Mitsuharu,Kambe, Nobuaki,Sonoda, Noboru
, p. 1018 - 1019 (2007/10/02)
Alk-4-enyl bromides and iodides 1, when treated with the tributyltin hydride/CO sustem, undergo carbonylative cyclization to give cyclopentanones in good yields (AIBN cat., benzene, 79-90 atm, = 0.025-0.05 mol dm-3, 80 deg C.
Base-Catalyzed Reactions of α,β-Unsaturated Esters and Nitriles. 4. Dimerization of β-Alkyl-Substituted Acrylates
Shabtai, Joseph,Ney-Igner, Eva
, p. 3795 - 3802 (2007/10/02)
2-Butenoates 1-C4 alkyl, cyclohexyl, or 1-bornyl> and higher β-alkyl-substituted acrylates 2-C9 n-alkyl> undergo highly selective (>95percent) dimerization in the presence of promoted potassium or sodium catalysts to yield corresponding 2-alkylidene-3-alkylglutarates (3).The reaction involves metalation of the β-alkylacrylate at the C-2 position, followed by addition at C-3 of a second monomeric molecule.Changes in the relative extent of dimerization (Kr) as a function of structural and experimentalvariables were determined.Kr is strongly dependent upon the inductive and steric characteristics of the alcoholic (R) group and of the β-alkyl substituent (R').For an n-alkyl group as R' the Kr value increases with increase in chain length from C1 to C4 but then decreases for longer substituents (C5-C9).Among the two geometric isomers in the dimeric product 3, the isomer with an α-vinylic hydrogen cis to the carboalkoxy group is predominant in all cases, but its relative concetration decreases with an increase in the size of R'.Branched or cyclic β-substituents in 2 prevent dimerization due to steric hindrance in the rate-determining addition step.Promoted potassium or sodium catalysts show much higher dimerization activity compared to supported alkali metals or to alkoxides.For conversions of up to 60percent, Kr values in proton-exchanging alkylbenzene solvents and in nonexchanging alkylcyclohexanes are closely similar, indicating faster abstraction of an α-vinylic hydrogen from the monomer, rather than a benzylic hydrogen from the solvent, in the chain regeneration step of the reaction.
Conversion of Enones into Dienones via Allylpalladium Complexes
Haynes, Richard K.,Jackson, Roy W.,Stragalinou, Anna
, p. 1537 - 1544 (2007/10/02)
A series of reagents for the conversion of enones into dienones via allylpalladium compounds has been studied and mild conditions for dienone preparation are recommended.
