28010-12-0Relevant academic research and scientific papers
HPLC and GC-MS identification of the major organic constituents in New Zealand propolis
Markham, Kenneth R.,Mitchell, Kevin A.,Wilkins, Alistair L.,Daldy, Julia A.,Lu, Yinrong
, p. 205 - 211 (1996)
The major organic constituents of New Zealand sourced propolis have been identified and quantified in tincture solutions by a combination of HPLC and GC-mass spectrometry (MS). HPLC was the preferred method for the analysis of flavonoids because of their very low response factors in GC-MS. Flavonoid levels ranged from 30-40 mg ml-1. A distinctive characteristic of the flavonoids in New Zealand propolis is the unusually high proportion (ca 70%) of dihydroflavonoids, e.g. pinocembrin, pinobanksin and pinobanksin 3-acetate. Non-flavonoid components analysed by GC-MS comprised a range of aromatic compounds (3-7.5 mg ml-1), together with low levels (0.25-0.78 mg ml-1) of fatty acids. The former comprised mainly cinnamic acids and their esters, but also included the rare 5-phenyl-trans-trans-2,4-pentadienoic acid and the new natural product, 5-phenyl-trans-3-pentenoic acid. Both were synthesized to confirm their identity. Copyright
Electrophilic Activation of α,β-Unsaturated Amides: Catalytic Asymmetric Vinylogous Conjugate Addition of Unsaturated γ-Butyrolactones
Zhang, Ming,Kumagai, Naoya,Shibasaki, Masakatsu
, p. 5525 - 5529 (2016)
Although catalytic asymmetric conjugate addition reactions have remarkably advanced over the last two decades, the application of less electrophilic α,β-unsaturated carboxylic acid derivatives in this useful reaction manifold remains challenging. Herein, we report that α,β-unsaturated 7-azaindoline amides act as reactive electrophiles to participate in catalytic diastereo- and enantioselective vinylogous conjugate addition of γ-butyrolactones in the presence of a cooperative catalyst comprising of a soft Lewis acid and a Br?nsted base. Reactions mostly reached completion with as little as 1 mol % of catalyst loading to give the desired conjugate adducts in a highly stereoselective manner.
Stereoregular two-dimensional polymers constructed by topochemical polymerization
Wang, Zhihan,Randazzo, Katelyn,Hou, Xiaodong,Simpson, Jeffrey,Struppe, Jochem,Ugrinov, Angel,Kastern, Brent,Wysocki, Erin,Chu, Qianli R.
, p. 2894 - 2900 (2015)
Two stereoregular 2D polyesters were synthesized by using topochemical polymerization of symmetric four-armed monomers. The monomers contain reactive carbon-carbon double bond(s) on each arm. The critical assemblies with multiple preorganized reactive centers were characterized by powder and single crystal X-ray diffraction. The solvent-free polymerization could be carried out with sunlight or UV irradiation. The locally confined photopolymerization process dimerized all of the olefins within the 2D bricklayer packing, which led to the formation of 2D polymers in the solid state. The process was monitored by FT-IR, and the products were confirmed by solid state NMR. After hydrolysis of the 2D polyester, the newly formed carbon-carbon single bonds during the [2 + 2] photocyclization were directly revealed by the single crystal structure of the hydrolysis product. Ultrathin sheets of the 2D polymer were observed under SEM and TEM after exfoliation.
Amino Group Functionalized Hf-Based Metal-Organic Framework for Knoevenagel-Doebner Condensation
Das, Aniruddha,Anbu, Nagaraj,Gogoi, Chiranjib,Dhakshinamoorthy, Amarajothi,Biswas, Shyam
, p. 3396 - 3403 (2021/08/20)
A Hf(IV) metal-organic framework (MOF) with di-amino functionalized linker was obtained as a crystalline solid with UiO-67 topology under solvothermal reaction conditions. The guest free form of Hf(IV) MOF (1′) was efficiently employed as a heterogeneous catalyst to synthesize cinnamic acid derivatives via Knoevenagel-Doebner reaction for the first time. The catalyst (1′) was efficiently active to directly achieve cinnamic acid from benzaldehyde and malonic acid. The solid retained its activity up to 6th cycle with no decay in its activity. The noticeable advantages of the catalyst are its milder reaction conditions, high yield, high stability, recyclable nature towards catalysis and wide substrate scope as well as shape-selective behaviour. The possible mechanism of the reaction was also studied thoroughly with suitable control experiments.
Photo-Promoted Decarboxylative Alkylation of α, β-Unsaturated Carboxylic Acids with ICH2CN for the Synthesis of β, γ-Unsaturated Nitriles
Pan, Chunxiang,Yang, Chunhui,Li, Kangkui,Zhang, Keyang,Zhu, Yuanbin,Wu, Shiyuan,Zhou, Yongyun,Fan, Baomin
supporting information, p. 7188 - 7193 (2021/10/01)
An efficient, catalyst/photocatalyst-free, and cost-effective methodology for the decarboxylative alkylation of α,β-unsaturated carboxylic acids to synthesize β,γ-unsaturated nitriles has been developed. The reaction proceeded in an environmentally benign atmosphere of blue light-emitting diode irradiation with K2CO3 and water at room temperature. The methodology worked for a wide range of substrates (22 examples) with up to 83% yield. The protocol is also compatible for gram-scale synthesis.
Enantioselective Redox-Divergent Chiral Phosphoric Acid Catalyzed Quinone Diels–Alder Reactions
Bernadat, Guillaume,Gelis, Coralie,Masson, Géraldine,Neuville, Luc,Retailleau, Pascal,Varlet, Thomas
supporting information, p. 8491 - 8496 (2020/04/10)
An efficient enantioselective construction of tetrahydronaphthalene-1,4-diones as well as dihydronaphthalene-1,4-diols by a chiral phosphoric acid catalyzed quinone Diels–Alder reaction with dienecarbamates is reported. The nature of the protecting group on the diene is key to the success of achieving high enantioselectivity. The divergent “redox” selectivity is controlled by using an adequate amount of quinones. Reversible redox switching without erosion of enantioselectivity was possible from individual redox isomers.
Reaction of 5-phenylpenta-2,4-dienoic acid with benzene in trifluoromethanesulfonic acid
Ismagilova, A. R.,Osetrova, L. V.,Vasilyev, A. V.,Zakusilo, D. N.
, p. 1928 - 1932 (2020/11/05)
The reaction of 5-phenylpenta-2,4-dienoic acid with benzene in CF3SO3H, depending on the reaction conditions, gives three products, namely, 5,5-diphenylpent-2-enoic acid and tetralone and indanone derivatives. These carbocyclic compo
Synthesis and characterization of unsaturated diacyl and alkyl-acyl piperazine derivatives
Sari, Sait,ünalan, Seda,Yilmaz, Mehmet
, p. 1656 - 1671 (2020/01/03)
The aim of this study is to obtain new unsaturated piperazine compounds by the reactions of piperazine (1a) and piperazine derivatives (1b–1d) with acylation reactive groups (2a–2j). Methacryloyl piperazine (1b) was synthesized from the reaction of methacrylic anhydride with piperazine (1a). Acyl chlorides (2b–2d) were prepared from the reaction of thionyl chloride with carboxylic acids (3a–3c) obtained as a result of the reaction with malonic acid and suitable aldehyde (5-methylfuran-2-carbaldehyde for 3a, cinnamaldehyde for 3b, and thiophene-2-carbaldehyde for 3c), respectively, by literature methods. Acyl chlorides 2e and 2f were obtained from the reaction of commercially purchased carboxylic acids 3d and 3e with thionyl chloride. Acyl chlorides (2g–2j) were synthesized from the reaction of thionyl chloride with carboxylic acids (3d–3g) transformed from hydrolyzation of esters (4a–4d) obtained as a result of the reaction of triethyl phosphonoacetate with a suitable ketone (acetophenone for 4a, benzophenone for 4b, 1-(5-methylfuran-2-yl)ethan-1-one for 4c, and 1-(thiophen-2-yl)ethan-1-one for 4d), respectively, by literature methods. Unsaturated piperazine derivatives 5a and 5b were obtained from the reaction of 1b with 2b and 2e, respectively. In addition, from the reaction of 1b and acyl chlorides (2b–2j), unsaturated piperazines (5c–5k) were synthesized in medium to good yields (63%–84%). Also, 5l–5g and 5r–5w were obtained from the reaction of allyl piperazine (2c) and cinnamyl piperazine (2d) with acyl chlorides (2a–2f).
Iron-Catalyzed Reactions of 2-Pyridone Derivatives: 1,6-Addition and Formal Ring Opening/Cross Coupling
Huang, Lin,Gu, Yiting,Fürstner, Alois
supporting information, p. 4017 - 4023 (2019/08/07)
In the presence of simple iron salts, 2-pyridone derivatives react with Grignard reagents under mild conditions to give the corresponding 1,6-addition products; if the reaction medium is supplemented with an aprotic dipolar cosolvent after the actual addition step, the intermediates primarily formed succumb to ring opening, giving rise to non-thermodynamic Z,E-configured dienoic acid amide derivatives which are difficult to make otherwise. Control experiments as well as the isolation and crystallographic characterization of a (tricarbonyl)iron pyridone complex suggest that the active iron catalyst generated in situ exhibits high affinity to the polarized diene system embedded into the heterocyclic ring system of the substrates, which likely serves as the actual recognition element.
Cis-cinnamic acid analogue, gravitropism modifier (by machine translation)
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Paragraph 0083-0087, (2019/11/30)
[Problem] cinnamic acid or cinnamic acid analogue comprising adjusting agent gravitropism cis. [Solution] cinnamic acid and/or cinnamic acid as an active ingredient to adjust gravitropism cis edge agents, cinnamic acid edge is, for example obtained by reacting compounds of the following formula. (In the formula, R is a phenyl group. )Figure 6 [drawing] (by machine translation)
