29304-63-0Relevant academic research and scientific papers
The effect of PEGylated dendrimers on the catalytic activity and stability of palladium particles in the suzuki reaction
Gaebler, Christian,Jeschke, Janine,Nurgazina, Gulnar,Dietrich, Sascha,Schaarschmidt, Dieter,Georgi, Colin,Schlesinger, Maik,Mehring, Michael,Lang, Heinrich
, p. 317 - 323 (2013)
Stable dendrimer-coated Pd particles were synthesized using the wet-chemical borohydride reduction method of Pd(II) salts in the presence of low-generation (poly)ethylene glycol-terminated amidoamine-based dendrimers. The identity and structure of the Pd-
Application of the ferrocene-containing chelated palladacycles as catalysts in the Suzuki reaction
Bulygina,Khrushcheva,Sokolov
, p. 258 - 260 (2011)
Two ferrocene-containing chelated palladacycles with the bi- and tridentate (C,N) and (C,N,N) ligands were used as catalysts in the Suzuki reaction. Both compounds were shown to be efficient catalysts.
MeOTf-catalyzed formal [4?+?2] annulations of styrene oxides with alkynes leading to polysubstituted naphthalenes through sequential electrophilic cyclization/ring expansion
Chen, Chao,Xi, Chanjuan,Zhang, Zeyu,Zou, Song
supporting information, (2021/12/30)
MeOTf-catalyzed formal [4 + 2] annulation of styrene oxides with alkynes to afford polysubstituted naphthalenes has been realized, which undergoes sequential electrophilic cyclization/ring expansion. A range of substrates were tolerated in the formation of naphthalene derivatives with high regioselectivity in satisfactory yields. The reaction could also be carried out on gram scale.
Triflic acid catalysed regioselective synthesis of substituted naphthalenes by benzannulation of carbonyls with alkynes
Gudla, Vanajakshi,Sudheer, Mokhamatam,Rao, Chinthu Joginarayana,Sanasi, Paul Douglas,Battula, Venkateswara Rao
, (2021/05/31)
An interesting and facile triflic acid catalysed annulation of α-aryl carbonyls with arylalkynes is presented for the regioselective synthesis of substituted naphthalenes. The annulation reaction involves a sequence of electrophilic attack of carbonyl on arylalkyne and benzannulation catalysed by triflic acid. The present catalyst effects this transformation at room temperature itself. Intramolecular version of the present Br?nsted acid catalysis furnished compounds containing 1-arylnaphthalene core fused with ring systems in excellent yields.
Monosubstituted, Anionic Imidazolyl Ligands from N?H NHC Precursors and Their Activity in Pd-Catalyzed Cross-Coupling Reactions
Clark, Kyle J.,Ess, Daniel H.,Jensen, Christopher A.,Kenney, Karissa C.,Larson, Alexandra J. S.,Martinez, Erin E.,Michaelis, David J.,Nazari, S. Hadi,Smith, Stacey J.,Valdivia-Berroeta, Gabriel A.
supporting information, (2020/07/06)
We report that treatment of several 2-diphenylphosphinoimidazoles with Pd(II) salts generates monosubstituted N?H NHC?Pd complexes via insertion into the C?P bond. Removal of the N?H proton in situ leads to anionic (X-type) or imidazolyl-Pd complexes that are highly stable and catalytically active, achieving up to 340,000 turnovers at 1 ppm catalyst loading in Suzuki-Miyaura reactions. DFT-calculated Tolman electronic parameters for the sterically small ligands suggest that these ligands are significantly more donating than traditional NHCs, which provides a rationale for rapid cross-coupling catalysis. Excellent reactivity is also demonstrated in Sonogashira reactions. (Figure presented.).
Photoaccelerated energy transfer catalysis of the Suzuki-Miyaura coupling through ligand regulation on Ir(iii)-Pd(ii) bimetallic complexes
Cao, Man-Li,Yao, Su-Yang,Zhang, Xiu-Lian
, p. 42874 - 42882 (2020/12/22)
Three bimetallic Ir(iii)-Pd(ii) complexes [Ir(ppy)2(bpm)PdCl2](PF6) (ppy = 2-phenylpyridine, 1), [Ir(dfppy)2(bpm)PdCl2](PF6) (dfppy = (4,6-difluorophenyl)pyridine, 2), and [Ir(pq)2(bpm)PdCl2](PF6) (pq = 2-phenylquinoline, 3) were synthesized by using 2,2′-bipyrimidine (bpm) as a bridging ligand. The influences of the cyclometalated ligand at the Ir(iii) center on the photophysical and electrochemical properties as well as photocatalytic activity for the Suzuki-Miyaura coupling reaction under mild conditions were evaluated. The results revealed that complex 3 enables dramatically accelerating the Suzuki-Miyaura coupling reaction under visible light irradiation at room temperature, due to the effective absorption of visible light and appropriate locus of the excited chromophore. Mechanism studies showed that the chromophore [Ir(pq)2(bpm)] fragment absorbs visible light to produce the triplet excited state centering on the bridging ligand which boosts the formation of electron rich Pd(ii) units and facilitates the oxidative addition step of the catalytic cycle. Simultaneously, the excited chromophore undergoes energy transfer efficiently to the Pd(ii) reaction site to form the excited Pd(ii) species, resulting in enhancement of Pd(ii) reduction steps of the Suzuki-Miyaura coupling reaction and increasing the reactivity of the catalyst. This provides a new strategy for designing photocatalysts for coupling reaction through altering the cyclometalated ligand to modulate the photophysical properties and the cooperation between two metal units.
Preparation method of aromatics methylation
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Paragraph 0084; 0085; 0086, (2019/11/20)
The invention relates to the technical field of organic synthesis or pharmaceutical chemistry, in particular to a preparation method of aromatics methylation. Under inert gas protection, a substrate A, a methylation reagent B and a termination agent C are used as starting materials, under the action of a catalyst D, a ligand E, a norborneene derivative G and a base F, the starting materials are subjected to a stirring reaction in an organic solvent H at 30-140 DEG C, and after the reaction, a reaction mixture is sucked and filtered, concentrated and purified to prepare a product of aromatics methylation shown as any formula of a formual I, a formual II and a formual III (please see the specifications for the formual I, the formual II and the formual III). According to the preparation method, related main raw materials are aryl iodide, trimethyl phosphate, methyl sulfonate, deuterated methyl ester sulfoacid, olefin, alkyne, an aryl boron compound, cyanide, bis(pinacolato)diboron and a proton source, the raw materials can be used as a commercial reagent without special treatment, the cost is low, and the variety is great. According to the method, aromatics methylation products can beprepared in large quantities (grams), and a good foundation is laid for industrial production.
Modular Dual-Tasked C-H Methylation via the Catellani Strategy
Gao, Qianwen,Shang, Yong,Song, Fuzhen,Ye, Jinxiang,Liu, Ze-Shui,Li, Lisha,Cheng, Hong-Gang,Zhou, Qianghui
supporting information, p. 15986 - 15993 (2019/10/11)
We report a dual-tasked methylation that is based on cooperative palladium/norbornene catalysis. Readily available (hetero)aryl halides (39 iodides and 4 bromides) and inexpensive MeOTs or trimethylphosphate are utilized as the substrates and methylating reagent, respectively. Six types of "ipso" terminations can modularly couple with this "ortho" C-H methylation to constitute a versatile methylation toolbox for preparing diversified methylated arenes. This toolbox features inexpensive methyl sources, excellent functional-group tolerance, simple reaction procedures, and scalability. Importantly, it can be uneventfully extended to isotope-labeled methylation by switching to the corresponding reagents CD3OTs or 13CH3OTs. Moreover, this toolbox can be applied to late-stage modification of biorelevant substrates with complete stereoretention. We believe these salient and practical features of our dual-tasked methylation toolbox will be welcomed by academic and industrial researchers.
N-Heterocarbene Palladium Complexes with Dianisole Backbones: Synthesis, Structure, and Catalysis
Li, Dong-Hui,He, Xu-Xian,Xu, Chang,Huang, Fei-Dong,Liu, Ning,Shen, Dong-Sheng,Liu, Feng-Shou
, p. 2539 - 2552 (2019/06/17)
A series of palladium N-heterocyclic carbenes (NHCs), complexes C1-C5, bearing dianisole backbones and substituted N-aryl moieties have been synthesized and characterized. The electronic effect as well as the steric environment of the NHC ligands has been assessed. The synthesized palladium complexes were applied for Suzuki-Miyaura cross-coupling reactions under aerobic conditions. The relationship between the catalytic structure and catalytic performance was then extensively investigated. Upon optimizing the reaction conditions, the C4 was found to be highly efficient to catalyze the cross-coupling of (hetero)aryl chlorides with (hetero)arylboronic acids at a 0.1 mol % palladium loading.
An efficient class of bis-NHC salts: Applications in Pd-catalyzed reactions under mild reaction conditions
Chiu, Chien-Cheng,Chiu, Hui-Tzu,Lee, Dong-Sheng,Lu, Ta-Jung
, p. 26407 - 26415 (2018/08/04)
This study describes an efficient class of bis-N-heterocyclic carbene (bis-NHC) salts that can be easily made from commercially available and inexpensive starting materials. The application of these salts to Pd-catalyzed reactions is described. The palladium (Pd) catalyst generated in situ was highly effective under mild reaction conditions.
