3901-07-3Relevant articles and documents
Production of stilbenoids and phenolic acids by the peanut plant at early stages of growth
Sobolev, Victor S.,Horn, Bruce W.,Potter, Thomas L.,Deyrup, Stephen T.,Gloer, James B.
, p. 3505 - 3511 (2006)
The peanut plant (Arachis hypogaea) is known to produce stilbene phytoalexins as a defensive response to fungal invasion; however, the distribution of phytoalexins among different organs of the peanut plant at early stages of growth under axenic conditions has not been studied. Axenic plants produced a stilbenoid, resveratrol, as well as soluble bound and free phenolic acids, including 4-methoxycinnamic acid, which is reported in peanuts for the first time. Neither resveratrol nor phenolic acids were found in the root mucilage; the prenylated stilbenes were restricted to the mucilage and were not found in other organs of the peanut plant. These findings may lead to a better understanding of the defensive role of peanut stilbenes and phenolic acids.
Reversion of alignment direction in the thermally enhanced photoorientation of photo-cross-linkable polymer liquid crystal films
Kawatsuki, Nobuhiro,Goto, Kohei,Kawakami, Tetsuro,Yamamoto, Tohei
, p. 706 - 713 (2002)
Reversion of the in-plane reorientation direction of mesogenic groups has been observed for the first time in novel polymethacrylate liquid crystal (PLC) films substituted with a 4-methoxycinnamoyloxybiphenyl side group. The reversion was generated by irradiation with linearly polarized ultraviolet (LPUV) light and a subsequent annealing. Irradiation with LPUV light induces negative optical anisotropy of the films as a result of an axis-selective photoreaction of the side groups. The direction of the thermally enhanced reorientation is dependent on the degree of photoreaction and the distribution of photoproducts, while the induced orientational order in both directions, S, was larger than 0.5. The distribution of photoproducts in PLC films has been analyzed to elucidate their contribution to the thermally enhanced reorientation behavior. Initially upon photoreaction, thermal enhancement of the photoinduced negative optical anisotropy was observed. However, when the degree of photodimerization was 15% or greater, the direction of the thermally enhanced reorientation was found to be parallel to the polarization direction (E) of LPUV light. It is concluded that a small amount of photoproduct plays a role in the thermal amplification of the photoinduced negative optical anisotropy in a manner identical to that of PLC with azobenzene side groups. In contrast, photodimerized mesogenic groups generated reversion of the orientational direction and enhancement of positive optical anisotropy of the film through annealing.
One-pot halogenation-Heck coupling reactions in ionic liquids
Handy, Scott T.
, p. 3176 - 3178 (2006)
Traditional cross-coupling approaches rely upon two steps - halogenation and coupling - each of which is viewed and conducted independently. In an effort to develop a one-pot approach, we have noted that the halogenation and Heck coupling reactions can both be conducted in a room-temperature ionic liquid without the need to isolate the halogenated intermediate. Application to several systems shows that this approach works well for moderately to highly electron-rich aromatics. Georg Thieme Verlag Stuttgart.
Palladium-catalyzed Heck reaction in perfluorinated solvents
Moineau, Johanne,Pozzi, Gianluca,Quici, Silvio,Sinou, Denis
, p. 7683 - 7686 (1999)
Palladium-catalyzed coupling reaction of aryl iodides with methyl acrylate, commonly designated as the Heck reaction, can be performed in perfluorinated solvents, using perfluorocarbon-soluble triarylphosphines as ligands. The easy separation and recyclin
Recoverable cationic Pd-catalyzed Heck reaction under thermomorphic mode
Li, Chieh-Keng,Ghalwadkar, Ajay,Lu, Norman
, p. 3637 - 3642 (2011)
The reaction of allylpalladium chloride dimer and 4,4′-bis(R fCH2OCH2)-2,2′-bpy, 1a-c, in the presence of AgOTf resulted in the synthesis of cationic complex, [Pd(η3-allyl)(4,4′-bis-(RfCHs
Constituents of the fungi Daedalea quercina and Daedaleopsis confragosa var. tricolor
Roesecke, Joachim,Koenig, Wilfried A
, p. 757 - 762 (2000)
Phytochemical examination of solvent extracts of the wood-rotting fungi Daedalea quercina and Daedaleopsis confragosa var. tricolor led to the isolation of five new triterpene derivatives and some known fungal constituents. All structures were identified
Phosphine-Functionalized Chitosan Microparticles as Support Materials for Palladium Nanoparticles in Heck Reactions
Biajoli, André F. P.,Fajardo, André R.,Lemos, Thalia S. A.,de Souza, Jaqueline F.
, (2022/01/11)
Herein, we investigated the activation and stabilization of Pd nanoparticles using microparticles of chitosan-functionalized with phosphine moieties. The catalytic activity of the prepared material was assessed in a series of Heck reactions, which demonst
Synthesis of novel 1-phenyl-benzopyrrolizidin-3-one derivatives and evaluation of their cytoneuroprotective effects against NMDA-induced injury in PC12 cells
Cao, Jiafu,Li, Qiji,Liao, Xiu,Wang, Enhua,Wang, Li,Yang, Juan,Yang, Lishou,Yang, Qian,Yang, Xiaosheng,Yang, Yan
supporting information, (2022/02/23)
A range of novel 1-phenyl-benzopyrrolizidin-3-one derivatives were synthesized and evaluated for neuroprotective effects against N-methyl-?-aspartate (NMDA)-induced injury in PC12 cells. Interestingly, derivatives that 1-phenyl moiety bearing electron-donating group, especially benzyloxy, and the trans-forms exhibited better protective activity against NMDA-induced neurotoxicity. Compound 11 m demonstrated the best neuroprotective potency and shown a dose-dependent prevention. The increased intracellular calcium (Ca2+) influx caused by NMDA in PC12 cells was reversed in the case of compound 11 m pretreatment at 15 μM. These results suggested that the synthesized 1-phenyl-benzopyrrolizidin-3-one derivatives exerted neuroprotective effect on NMDA-induced excitotoxicity in PC12 cells associated with inhibition of Ca2+ overload and can be further optimized for the development of neuroprotective agents.
Pd-Catalyzed desulfitative arylation of olefins by: N -methoxysulfonamide
Ojha, Subhadra,Panda, Niranjan
supporting information, p. 1292 - 1298 (2022/02/19)
A novel Pd-catalyzed protocol for the desulfitative Heck-type reaction of N-methoxy aryl sulfonamides with alkenes was reported. The cross-coupling reaction was performed successfully with a variety of olefins to obtain aryl alkenes. Different substituents on the aromatic ring of N-methoxysulfonamides were also found to be compatible with the reaction conditions. Expectedly, the reaction proceeds through CuCl2-promoted generation of the nitrogen radical and subsequent desulfonylation under thermal conditions to afford the aryl radical for the Pd-catalyzed coupling reaction. N-Methoxysulfonamide was further exploited for the synthesis of symmetrical biaryls in the presence of CuCl2. This journal is
Coordination from Heteroscorpionate Ligand Towards Pd(II) via Pd???Hδ?C(sp3) Interaction: Structural and Catalytic Studies
Castillo-Moreno, Miguel ángel,Cruz-Borbolla, Julián,González-Montiel, Simplicio,Ignacio Sandoval-Chávez, César,Manuel Vásquez-Pérez, José,Mendoza-Espinosa, Daniel,Salazar-Pereda, Verónica
supporting information, p. 2661 - 2668 (2021/07/06)
The coordination ability of the heteroscorpionate ligand 2,2-bis(3,5-dimethylpyrazol-1-yl)-1-p-tolylethanol (1) towards palladium (II) dihalides was evaluated. The structures of the respective palladium complexes (2 and 3) were elucidated in solution by NMR spectroscopy, and their molecular structures were established by single crystal X-ray diffraction analyses. Both studies revealed the existence of Pd???Hδ?C(sp3) anagostic interactions. The molecular structure of complexes 2 and 3 displays coordination of ligand 1 to palladium in a κ3-NNH tridentate fashion via two nitrogen atoms and one δ-anagostic H???Pd interaction. The metal center exhibits a square pyramidal geometry. The distances of anagostic Hδ???Pd interactions ranged from 2.566 to 2.576 ?. The δ-anagostic H???Pd interactions in complexes 2 and 3 were also identified by Bader's quantum theory of atoms in molecules (QTAIM) and non-covalent interaction (NCI) analysis. The catalytic efficiencies of complexes 2 and 3 in the Suzuki-Miyaura cross-coupling reactions were evaluated and the results showed that palladium (II) dibromide complex is the most efficient of the series. Complex 3 was also evaluated in Mizoroki-Heck cross-coupling reactions.
