5043-91-4Relevant academic research and scientific papers
N-Methylphenothiazine S-Oxide Enabled Oxidative C(sp2)–C(sp2) Coupling of Boronic Acids with Organolithiums via Phenothiaziniums
Yoshida, Tatsuki,Honda, Yuki,Morofuji, Tatsuya,Kano, Naokazu
, p. 9664 - 9668 (2021/12/17)
Herein, we report the development of a transition-metal-free oxidative C(sp2)–C(sp2) coupling of readily available boronic acids and organolithiums via phenothiazinium ions. Various biaryl, styrene, and diene derivatives were obtained using this reaction system. The key to this process is N-methylphenothiazine S-oxide (PTZSO), which allows efficient conversion of boronic acids to phenothiazinium ions. The mechanism of phenothiazinium formation using PTZSO was investigated using theoretical calculations and experiments, which provided insight into the unique reactivity of PTZSO.
Transition-Metal-Free Matsuda-Heck Type Cross-Coupling and Mechanistic Evidence for a Radical Mechanism
Bergès, Julien,Zaid, Yassir,Tlili, Anis,Sotiropoulos, Jean-Marc,Taillefer, Marc
supporting information, p. 1559 - 1563 (2021/02/27)
The Matsuda-Heck reaction, usually performed with palladium catalysts, can be carried out under transition-metal-free conditions in the presence of a KOtBu/DMF couple. This system allows the selective and direct synthesis of stilbenes from aryldiazonium salts under mild temperature (20 °C). Mechanistic studies suggest a radical pathway in which the DMF acts as the initiator of the overall process.
Synthesis, crystal structure, and catalytic activity of bridged-bis(N-heterocyclic carbene) palladium(II) complexes in selective Mizoroki-Heck cross-coupling reactions
El Ali, Bassam,Fettouhi, Mohammed,Iali, Wissam,Mansour, Waseem,Suleiman, Rami
, (2021/08/09)
A series of three 1,3-propanediyl bridged bis(N-heterocyclic carbene)palladium(II) complexes (Pd-BNH1, Pd-BNH2, and Pd-BNH3), with + I effect order of the N-substituents of the ligand (isopropyl > benzyl > methoxyphenyl), was the subject of a spectroscopic, structural, computational and catalytic investigation. The bis(NHC)PdBr2 complexes were evaluated in Mizoroki-Heck coupling reactions of aryl bromides with styrene or acrylate derivatives and showed high catalytic efficiency to produce diarylethenes and cinnamic acid derivatives. The X-ray structure of the most active palladium complex Pd-BNH3 shows that the Pd(II) center is bonded to the two carbon atoms of the bis(N-heterocyclic carbene) and two bromide ligands in cis position, resulting in a distorted square planar geometry. The NMR data of Pd-BNH3 are consistent with a single chair-boat rigid conformer in solution with no dynamic behavior of the 8-membered ring palladacycle in the temperature range 25–120 °C. The catalytic activities of three Pd-bridged bis(NHC) complexes in the Mizoroki-Heck cross-coupling reactions were not found to have a direct correlation with +I effect order of the N-substituents of the ligand. However, a direct correlation was found between the DFT calculated absolute softness of the three complexes with their respective catalytic activity. The highest calculated softness, in the case of Pd-BNH3, is expected to favor the coordination steps of both the soft aryl bromides and alkenes in the Heck catalytic cycle.
Dual ligand-promoted palladium-catalyzed nondirected C-H alkenylation of aryl ethers
Fu, Manlin,Liu, Jiang,Wang, Lei,Yin, Biao,Zhu, Qing
supporting information, p. 3293 - 3296 (2020/04/02)
Direct C-H functionalization of aryl ethers remains challenging owing to their low reactivity and selectivity. Herein, a novel strategy for nondirected C-H alkenylation of aryl ethers promoted by a dual ligand catalyst was demonstrated. This catalytic system readily achieved the highly efficient alkenylation of alkyl aryl ethers (anisole, phenetole, n-propyl phenyl ether, n-butyl phenyl ether and benzyl phenyl ether), cyclic aryl ethers (1,4-benzodioxan, 2,3-dihydrobenzofuran, dibenzofuran), and diphenyl oxides. Moreover, the proposed methodology was successfully employed for the late-stage modification of complex drugs containing the aryl ether motif. Interestingly, the compounds developed herein displayed fluorescent properties, which would facilitate their biological applications.
Diarylethene synthesis method without transition metal catalysis
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Paragraph 0041-0045, (2019/02/06)
The invention discloses a diarylethene synthesis method without transition metal catalysis. The method comprises the following steps: a cinnamic acid derivative and aryl trifluoroborate are subjectedto a decarboxylation coupling reaction in a solvent under the action of an oxidizing agent, postprocessing is performed after the reaction, and diarylethene is obtained. K2S2O8 is adopted to promote acatalytic system in the synthetic method, and a free radical coupling reaction can be performed directly under the condition that no ligand, transition metal or alkali is added. The method has widersubstrate range and higher yield; the method is simple to operate, reaction conditions are mild, and large-scale application is facilitated.
Preparation method of palladium catalyzed 1,2-trans diaryl alkene
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Paragraph 0043-0045, (2019/06/11)
The invention discloses a preparation method of palladium catalyzed 1,2-trans diaryl alkene. The method comprises the following steps that under the effects of catalysts, cocatalysts and alkali, arylacrylic acid and aromatic esters p-toluene sulfonate take decarboxylation coupling reaction in an organic solvent; after the reaction is finished, the 1,2-trans diaryl alkene is obtained through posttreatment. The method has the advantages that through C-O bond fracture, the operation is simple; a stable palladium catalyst with low cost is used; the substrate applicability is high; the harsh reaction conditions and the addition of strong alkali are not needed; the trans 1,2-diaryl alkene can be generated at high selectivity.
Palladium-catalyzed decarboxylative coupling of α,β-unsaturated carboxylic acids with aryl tosylates
Zhang, Wei,Chen, Gairong,Wang, Kaikai,Xia, Ran
, (2019/04/27)
We report a general method for selective cross-coupling of α,β-unsaturated carboxylic acids with aryl tosylates enabled by versatile Pd(II) complexes. This method features the general cross-coupling of ubiquitous α,β-unsaturated carboxylic acids by decarboxylation. The transformation is characterized by its operational simplicity, the use of inexpensive, air-stable Pd(II) catalysts, scalability and wide substrate scope. The reaction proceeds with high trans selectivity to furnish valuable (E)-1,2-diarylethenes.
Palladium nanoparticles immobilized on Schiff base-functionalized mesoporous silica as a highly efficient and magnetically recoverable nanocatalyst for Heck coupling reaction
Khodaei, Mohammad Mehdi,Dehghan, Mahsa
, (2018/10/26)
A new magnetically recoverable nanocatalyst was prepared by functionalization of mesoporous silica (SBA-15) with a Schiff base ligand, and then immobilization of palladium nanoparticles on it using a simple procedure. This heterogeneous catalyst was fully characterized using appropriate analyses and its catalytic efficiency was investigated in Heck reaction using iodo-, bromo- and chlorobenzene derivatives and styrene, with the aim of synthesizing stilbene derivatives, a class of compounds with a variety of pharmacological properties. Some of the characteristics of this nanocatalyst include good dispersion of palladium nanoparticles on the SBA-15 support, easy separation, catalyses the production of stilbene derivatives in a short time with excellent yields even for bromo- and chlorobenzene, and preservation of its catalytic activity after eight reaction cycles.
A tailored polymeric cationic tag-anionic Pd(ii) complex as a catalyst for the low-leaching Heck-Mizoroki coupling in flow and in biomass-derived GVL
Mahmoudi, Hamed,Valentini, Federica,Ferlin, Francesco,Bivona, Lucia Anna,Anastasiou, Ioannis,Fusaro, Luca,Aprile, Carmela,Marrocchi, Assunta,Vaccaro, Luigi
supporting information, p. 355 - 360 (2019/01/28)
The [PdCl4]2- palladium complex has been immobilized on a polystyrene-type resin loaded with pincer-type imidazolium ionic tag binding sites. The catalytic system (Pd(ii)-POLI-TAG) has proved to be highly active in the definition of an efficient protocol for the Heck-Mizoroki coupling reaction under batch and flow conditions. Importantly, it is shown to be highly robust in combination with a safe non-toxic reaction medium, i.e. biomass-derived GVL, since it could be reused for multiple runs without significantly losing its activity.
Facile synthesis of a recyclable Pd-rGO/CNT/CaFe2O4 nanocomposite with high multifunctional photocatalytic activity under visible light irradiation
Bagherzadeh, Mojtaba,Kaveh, Reyhaneh,Mahmoudi, Hamed
, p. 16257 - 16266 (2019/07/16)
We report a facile method to synthesize a magnetically separable Pd-rGO/CNT/CaFe2O4 photocatalyst. The incorporation of CNTs into rGO can form a conductive network structure to bridge the gaps between rGO sheets. This conductive netw
