74124-86-0Relevant academic research and scientific papers
Reduction of Electron-Deficient Alkenes Enabled by a Photoinduced Hydrogen Atom Transfer
Larionova, Natalia A.,Ondozabal, Jun Miyatake,Cambeiro, Xacobe C.
supporting information, p. 558 - 564 (2020/12/07)
Direct hydrogen atom transfer from a photoredox-generated Hantzsch ester radical cation to electron-deficient alkenes has enabled the development of an efficient formal hydrogenation under mild, operationally simple conditions. The HAT-driven mechanism is supported by experimental and computational studies. The reaction is applied to a variety of cinnamate derivatives and related structures, irrespective of the presence of electron-donating or electron-withdrawing substituents in the aromatic ring and with good functional group compatibility. (Figure presented.).
Harnessing Applied Potential: Selective β-Hydrocarboxylation of Substituted Olefins
Alkayal, Anas,Buckley, Benjamin R.,Malkov, Andrei V.,Montanaro, Stephanie,Tabas, Volodymyr,Wright, Iain A.
supporting information, (2020/02/13)
The construction of carboxylic acid compounds in a selective fashion from low value materials such as alkenes remains a long-standing challenge to synthetic chemists. In particular, β-addition to styrenes is underdeveloped. Herein we report a new electrosynthetic approach to the selective hydrocarboxylation of alkenes that overcomes the limitations of current transition metal and photochemical approaches. The reported method allows unprecedented direct access to carboxylic acids derived from β,β-trisubstituted alkenes, in a highly regioselective manner.
Palladium-Catalyzed Alkoxycarbonylation of sec-Benzylic Ethers
Beller, Matthias,Jackstell, Ralf,Maes, Bert U. W.,Schneider, Carolin
, (2020/02/25)
Herein, we report the palladium-catalyzed synthesis of 3-arylpropionate esters starting from secondary benzylic ethers. With this investigation it could be shown that ethers are suitable starting materials in addition to the established carbonylation reactions of olefins, alcohols, or aryl halides.
Cobalt(II)-Catalyzed Alkoxycarbonylation of Aliphatic Amines via C-N Bond Activation
Li, Chong-Liang,Jiang, Xuan,Lu, Liang-Qiu,Xiao, Wen-Jing,Wu, Xiao-Feng
supporting information, p. 6919 - 6923 (2019/09/07)
The first cobalt-catalyzed deaminative alkoxycarbonylation reaction was described for the conversion of readily available primary alkyl amines to synthetically versatile esters with moderate to high yields. This transformation shows good functional group compatibility and can serve as a powerful tool for the modification of alkyl amine-containing complex natural products and drug molecules.
Synthesis of N-Substituted Condensed Tetrahydropyridine-Based Enaminones via Palladium-Catalyzed Intramolecular C–N Cross-coupling
Dou?ová, Hana,R??i?ková, Zdeňka,?im?nek, Petr
, p. 670 - 684 (2018/01/22)
A number of β-enaminones with secondary amino group (alkyl, cyclopropyl, and aryl) were prepared from corresponding β-diketones. Two general protocols for their palladium-catalyzed intramolecular C–N cross-coupling were established to give corresponding N-substituted condensed tetrahydropyridines in good yields. The methodology is applicable for a wide variety of structural motifs. The work also extends the applicability of novel, recently established, palladium precatalysts to new substrates.
Comparison of Phenylacetates with Benzoates and Phenylpropanoates as Antifeedants for the Pine Weevil, Hylobius abietis
Unelius, C. Rikard,Bohman, Bj?rn,Nordlander, G?ran
, p. 11797 - 11805 (2018/11/21)
This study concludes an extensive investigation of antifeedants for the pine weevil, Hylobius abietis (Coleoptera: Curculionidae), an economically important pest of planted conifer seedlings. Building on the previously reported antifeedant effects of benzoates and phenylpropanoids (aromatic compounds with one- or three-carbon-atom substituents on the benzene ring), we here report the antifeedant effects of compounds with two-carbon-atom side chains (i.e., phenylacetates). We also present new results; the best antifeedants from the benzoate class were tested at 10-fold lower concentrations in order to find the optimal antifeedants. Generally, for all three compound classes, efficient antifeedants were found to have one or two methyl, chloro, or methoxy substituents on the aromatic ring. For monosubstituted phenylpropanoids, the substituent preferably should be in the para-position. In the search for synergistic antifeedant effects among the three compound classes, combinations of compounds from the three classes were tested in binary and ternary mixtures.
An intramolecular C-N cross-coupling of β-enaminones: A simple and efficient way to precursors of some alkaloids of Galipea officinalis
Douov, Hana,Hork, Radim,Ruikov, Zdeka,imunek, Petr
, p. 884 - 892 (2015/08/24)
2-Aroylmethylidene-1,2,3,4-tetrahydroquinolines with the appropriate substituents can be suitable precursors for the synthesis of alkaloids from Galipea officinalis (cuspareine, galipeine, galipinine, angustureine). However, only two, rather low-yielding procedures for their synthesis are described in the literature. We have developed a simple and efficient protocol for an intramolecular, palladium or copper-catalysed amination of both chloro- and bromo-substituted 3-amino-1,5-diphenylpent-2-en-1-ones leading to the above-mentioned tetrahydroquinoline moiety. The methodology is superior to the methods published to date.
Structure-activity relationships of phenylpropanoids as antifeedants for the pine weevil Hylobius abietis
Bohman,Nordlander,Nordenhem,Sunnerheim,Borg-Karlson,Unelius
, p. 339 - 352 (2008/09/18)
Ethyl cinnamate has been isolated from the bark of Pinus contorta in the search for antifeedants for the pine weevil, Hylobius abietis. Based on this lead compound, a number of structurally related compounds were synthesized and tested. The usability of the Topliss scheme, a flow diagram previously used in numerous structure-activity relationship (SAR) studies, was evaluated in an attempt to find the most potent antifeedants. The scheme was initially followed stepwise; subsequently, all compounds found in the scheme were compared. In total, 51 phenylpropanoids were tested and analyzed for SARs by using arguments from the field of medicinal chemistry (rational drug design). Individual Hansch parameters based on hydrophobicity, steric, and electronic properties were examined. The effects of position and numbers of substituents on the aromatic ring, the effects of conjugation in the molecules, and the effects of the properties of the parent alcohol part of the esters were also evaluated. It proved difficult to find strong SARs derived from single physicochemical descriptors, but our study led to numerous new, potent, phenylpropanoid antifeedants for the pine weevil. Among the most potent were methyl 3-phenylpropanoates monosubstituted with chloro, fluoro, or methyl groups and the 3,4-dichlorinated methyl 3-phenylpropanoate.
Aromatic chlorination of ω-phenylalkylamines and ω- phenylalkylamides in carbon tetrachloride and α,α,α- trifluorotoluene
O'Connell, Jenny L.,Simpson, Jamie S.,Dumanski, Paul G.,Simpson, Gregory W.,Easton, Christopher J.
, p. 2716 - 2723 (2008/02/08)
The aromatic halogenation of simple alkylbenzenes with chlorine proceeds smoothly in acetic acid but is much less efficient in less polar solvents. By contrast chlorination of ω-phenylalkylamines, such as 3-phenylpropylamine, occurs readily in either acetic acid, carbon tetrachloride or α,α,α-trifluorotoluene, and in the latter solvents gives high proportions of ortho-chlorinated products. These effects are attributable to the involvement of N-chloroamines as reaction intermediates, with intramolecular delivery of the chlorine electrophile. ω-Phenylalkylamides, such as 3-phenylpropionamide, also easily undergo aromatic chlorination in carbon tetrachloride and α,α,α-trifluorotoluene. These reactions generally show a first-order dependence on the substrate concentration, but not on the amount of chlorine. With carbon tetrachloride, very similar reaction rates are observed with chlorine concentrations ranging from 0.1-1.5 M. In α,α,α-trifluorotoluene, the rates reach a plateau at a chlorine concentration of approximately 0.2 M. These features indicate that the reactions proceed via the formation of intermediates which evidence suggests may be the corresponding O-chloroimidates. Irrespective of the mechanistic details, the reactions are remarkably rapid, being faster than analogous reactions in acetic acid and three to four orders of magnitude more rapid than reactions of simple alkylbenzenes in carbon tetrachloride. Therefore, chlorination of the amines and amides may be accomplished without the need for highly polar solvents, added catalysts or large excesses of chlorine, which are often employed for electrophilic aromatic substitutions. Although the use of carbon tetrachloride is becoming increasingly impractical due to environmental concerns, the trifluorotoluene is a suitable alternative. The Royal Society of Chemistry 2006.
On rearrangements by cyclialkylations of arylpentanols to 2,3-dihydro-1H-indene derivatives. Part 1. An unexpected rearrangement by the acid-catalyzed cyclialkylation of 4-(2-chlorophenyl)-2,4-dimethyl pentan-2-ol under formation of trans-4-chloro-2,3-dih
Blum, Roger,Giovannini, Edgardo,Hengartner, Urs,Vallat, Gabriel
, p. 1827 - 1840 (2007/10/03)
The acid-catalyzed cyclialkylation of 2,4-dimethyl-4-phenylpentan-2-ol led exclusively to the expected product, 2,3-dihydro-1,1,3,3-tetramethyl-1H-indene. However, analogous cyclialkylation of 4-(2-chlorophenyl)-2,4-dimethylpentan-2-ol (1) gave a ca. 1:1
