718-25-2Relevant academic research and scientific papers
Suzuki coupling reactions in neat water as the solvent: Where in the biphasic reaction mixture do the catalytic reaction steps occur?
Roehlich, Christoph,Wirth, Andreas S.,Koehler, Klaus
, p. 15485 - 15494 (2012)
Many reports on water-compatible palladium catalysts have appeared in the recent literature. For hydrophobic substrates, mixtures with pure water are biphasic, and it is widely not regarded that the elusive locality of the catalytic process (in water, the
One-Pot Dual Catalysis of a Photoactive Coordination Polymer and Palladium Acetate for the Highly Efficient Cross-Coupling Reaction via Interfacial Electron Transfer
Guo, Zhifen,Liu, Xin,Che, Yan,Chen, Dashu,Xing, Hongzhu
supporting information, p. 2695 - 2705 (2022/02/14)
We report herein an exploration of the straightforward one-pot dual-catalysis strategy, i.e., direct combination of a photoactive coordination polymer (CP) with another metal catalyst, for carrying out the desirable photoinduced organic transformation. Th
Heterobimetallic Pd/Mn and Pd/Co complexes as efficient and stereoselective catalysts for sequential Cu-free Sonogashira coupling–alkyne semi-hydrogenation reactions
Baweja, Saral,Clauss, Reike,Gelman, Dmitri,Hey-Hawkins, Evamarie
, p. 1344 - 1356 (2022/02/03)
A series of heterobimetallic PdII/MII complexes (MII = Mn, Co) were synthesised and tested as precatalysts for sequential Sonogashira coupling–alkyne semi-hydrogenation reactions to form Z-aryl alkenes. The carbometalated heterobimetallic PdII/CoII complex CoPdL3′ demonstrated an apparent cooperative effect compared to the corresponding monometallic counterparts. This compound was identified as a potent single-molecule catalyst for the one-pot Cu-free Sonogashira coupling of aryl bromides with terminal alkynes followed by chemo- and stereoselective semi-hydrogenation of the alkyne intermediate using NH3·BH3 as a hydrogen source. Furthermore, different aromatic substrates have been tested to show the generality of the reaction for the synthesis of Z-alkenes, including biologically active combretastatin A-4. In addition, the homogeneous nature of the catalytically active species was demonstrated.
Pd-Catalyzed Coupling of N-Tosylhydrazones with Benzylic Phosphates: Toward the Synthesis of Di- or Tri-Substituted Alkenes
Zhang, Kena,Provot, Olivier,Alami, Mouad,Tran, Christine,Hamze, Abdallah
, p. 1249 - 1261 (2022/02/07)
This study shows that various di- and tri-substituted alkenes with high chemoselectivity were obtained in good to high yields by coupling N-tosylhydrazones (NTHs) with benzylic phosphates as electrophilic partners. The obtained new catalytic system consis
Palladium nanoparticlesin situsynthesized onCyclea barbatapectin as a heterogeneous catalyst for Heck coupling in water, the reduction of nitrophenols and alkynes
Le, Van-Dung,Le, T. Cam-Huong,Chau, Van-Trung,Le, T. Ngoc-Duyen,Dang, Chi-Hien,Vo, T. To-Nguyen,Nguyen, Trinh Duy,Nguyen, Thanh-Danh
, p. 4746 - 4755 (2021/03/22)
This study develops an effective method for thein situsynthesis of palladium nanoparticles (PdNPs) usingCyclea barbatapectin as a green reducing and stabilizing reagent. The PdNP@pectin nanocomposite was well characterized by analysis techniques such as UV-vis, FTIR, EDX, XRD, SEM, HR-TEM and STEM-mapping. Crystalline PdNPs were found to be distributed in the size range of 1-25 nm with the highest frequency of 6-12 nm. PdNP@pectin exhibited excellent recyclable catalysis activity for the Heck coupling reaction in water medium. The kinetics and recyclability of nanoparticles were investigated for the catalytic reduction ofo-,m- andp-nitrophenol. The result showed a good catalysis efficiency with five successful recycles without compromising much. In particular, the nanocomposite was used as a catalyst for the conversion of alkynes intocis-alkenes with KOH/DMF as a hydrogenation source. The reaction was also utilized effectively for the synthesis of sex pheromones, includingPlutella xylostella((Z)-11-hexadecen-1-yl acetate) andCylas formicarius((Z)-3-dodecen-1-yl(E)-2-butenoate) with the total yields of 70% and 68%, respectively. Therefore, PdNPs supported onC. barbatapectin are promising catalysis materials for application in various fields.
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.
METHODS OF ARENE ALKENYLATION
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Page/Page column 18; 21-22; 42-43; 45, (2021/11/26)
The present disclosure provides for a rhodium-catalyzed oxidative arene alkenylation from arenes and styrenes to prepare stilbene and stilbene derivatives. For example, the present disclosure provides for method of making arenes or substituted arenes, in particular stilbene and stilbene derivatives, from a reaction of an optionally substituted arene and/or optionally substituted styrene. The reaction includes a Rh catalyst or Rh pre-catalyst material and an oxidant, where the Rh catalyst or Rh catalyst formed Rh pre-catalyst material selectively functionalizes CH bond on the arene compound (e.g., benzene or substituted benzene).
A Bis (BICAAC) Palladium(II) Complex: Synthesis and Implementation as Catalyst in Heck-Mizoroki and Suzuki-Miyaura Cross Coupling Reactions
Chakrabortty, Soumyadeep,Kaur, Mandeep,Adhikari, Manu,Manar, Krishna K.,Singh, Sanjay
supporting information, p. 6209 - 6217 (2021/05/06)
Carbenes are one of the most appealing, well-explored, and exciting ligands in modern chemistry due to their tunable stereoelectronic properties and a wide area of applications. A palladium complex (BICAAC)2PdCl2 with a recently discovered cyclic (alkyl)(amino)carbene having bicyclo[2.2.2] octane skeleton (BICAAC) was synthesized and characterized. The enhanced σ-donating and π-accepting ability of this carbene lend a hand to form a robust Pd-carbene bond, which allowed us to probe its reactivity as a precatalyst in Heck-Mizoroki and Suzuki-Miyaura cross-coupling reactions with low catalyst loading in open-air conditions. The diverse range of substrates was explored for both the cross-coupling reactions. To get a better understanding of the catalytic reactions, several analytical techniques such as field-emission scanning electron microscopy, high-resolution transmission electron microscopy, and powder X-ray diffraction were employed in a conclusive manner.
Energy-Transfer-Mediated Photocatalysis by a Bioinspired Organic Perylenephotosensitizer HiBRCP
Zhang, Yan,Xia, Mingze,Li, Min,Ping, Qian,Yuan, Zhenbo,Liu, Xuanzhong,Yin, Huimin,Huang, Shuping,Rao, Yijian
, p. 15284 - 15297 (2021/11/01)
Energy transfer plays a special role in photocatalysis by utilizing the potential energy of the excited state through indirect excitation, in which a photosensitizer determines the thermodynamic feasibility of the reaction. Bioinspired by the energy-transfer ability of natural product cercosporin, here we developed a green and highly efficient organic photosensitizer HiBRCP (hexaisobutyryl reduced cercosporin) through structural modification of cercosporin. After structural manipulation, its triplet energy was greatly improved, and then, it could markedly promote the efficient geometrical isomerization of alkenes from the E-isomer to the Z-isomer. Moreover, it was also effective for energy-transfer-mediated organometallic catalysis, which allowed realization of the cross-coupling of aryl bromides and carboxylic acids through efficient energy transfer from HiBRCP to nickel complexes. Thus, the study on the relationship between structural manipulation and their photophysical properties provided guidance for further modification of cercosporin, which could be applied to more meaningful and challenging energy-transfer reactions.
A photocatalyst-free visible-light-mediated solvent-switchable route to stilbenes/vinyl sulfones from β-nitrostyrenes and arylazo sulfones
Chawla, Ruchi,Dutta, P. K.,Jaiswal, Shefali,Yadav, Lal Dhar S.
supporting information, p. 6487 - 6492 (2021/08/03)
Photocatalyst-free visible-light-mediated reactions, based on the presence of a visible-light-absorbing functional group in the starting material itself in order to exclude the often costly, hazardous, degradable and difficult to remove or recover photoredox catalysts, have been gaining momentum recently. We have employed this approach to develop a denitrative photocatalyst-free visible-light-mediated protocol for the arylation/sulfonylation of β-nitrostyrenes employing arylazo sulfones (bench-stable photolabile compounds) in a switchable solvent-controlled manner. Arylazo sulfones served as the aryl and sulfonyl radical precursors under blue LED irradiation for the synthesis oftrans-stilbenes and (E)-vinyl sulfones in CH3CN and dioxane/H2O 2?:?1, respectively. The absence of any metal, photocatalyst and additive; excellent selectivity (E-stereochemistry) and solvent-switchability; and the use of visible light and ambient temperature are the prime assets of the developed method. Moreover, we report the first photocatalyst-free visible light-driven route to synthesize stilbenes and vinyl sulfones from readily available β-nitrostyrenes.
