5698-49-7Relevant academic research and scientific papers
Recyclable and reusable PdCl2(PPh3)2/PEG-400/H2O system for the hydrophenylation of alkynes with sodium tetraphenylborate
Liu, Rong,Zhang, Tingli,Huang, Bin,Cai, Mingzhong
, p. 172 - 178 (2020/07/04)
A stable and efficient PdCl2(PPh3)2/PEG-400/H2O catalytic system for the hydrophenylation reaction of alkynes has been developed. In the presence of 3 mol% PdCl2(PPh3)2 and 2 equiv. of HOAc, the hydrophenylation of both terminal and internal alkynes with sodium tetraphenylborate proceeded smoothly in a mixture of PEG-400 and water at room temperature or 50 °C to afford a variety of phenyl-substituted alkenes in moderate to high yields. The isolation of the products was easily performed by extraction with petroleum ether, and the PdCl2(PPh3)2/PEG-400/H2O system could be readily recycled and reused six times without apparent loss of catalytic activity.
Bimolecular vinylation of arenes by vinyl cations
Bour, Christophe,Gandon, Vincent,Li, Zhilong
supporting information, p. 6507 - 6510 (2020/07/02)
Styrene derivatives can be easily synthesized from vinyl triflates and arenes under mild reaction conditions, using [Li][Al(OC(CF3)3)4] as a catalyst and LiHMDS as a base. This transformation is likely to involve a vinyl cation intermediate as an electrophile, which is corroborated by DFT calculations, deuterium-labeling and other control experiments. The use of an inert weakly coordinating anion is a decisive factor in this bimolecular vinylation process. This journal is
A Highly Reduced Ni-Li-Olefin Complex for Catalytic Kumada-Corriu Cross-Couplings
Nattmann, Lukas,Lutz, Sigrid,Ortsack, Pascal,Goddard, Richard,Cornella, Josep
supporting information, p. 13628 - 13633 (2018/10/24)
The catalytic activity of a highly reduced Ni catalyst in the context of a Kumada-Corriu cross-coupling has been studied. This nickel complex is characterized by its high electron density, stabilized by simple olefin ligands in combination with two Li ions. Landmark reactivity has been found with this precatalyst which operates at cryogenic temperatures, thus allowing the presence of sensitive functionalities. Structural elucidation of oxidative addition intermediates and their reactivity suggest highly reduced species being operative in the C-C bond forming event.
Conjugated Microporous Polymer as Heterogeneous Ligand for Highly Selective Oxidative Heck Reaction
Zhou, Yun-Bing,Wang, Yu-Qing,Ning, Li-Chao,Ding, Zong-Cang,Wang, Wen-Long,Ding, Cheng-Ke,Li, Ren-Hao,Chen, Jun-Jia,Lu, Xin,Ding, Yun-Jie,Zhan, Zhuang-Ping
supporting information, p. 3966 - 3969 (2017/03/27)
A series of pyridine-type ligands containing C C bonds were designed and synthesized for selective oxidative Heck reaction. These ligands were utilized as functional units and integrated into the skeleton of conjugated microporous polymers. 6,6′-diiodo-2,2′-bipyridine and 1,3,5-triethynylbenzene were polycondensed via Sonogashira cross-coupling strategy to afford CMP-1 material. The resultant CMP-1 was used as a heterogeneous catalytic ligand for the PdII-catalyzed oxidative Heck reaction with high linear selectivity. The linear selectivity of CMP-1 is about 30 times higher than that of bipyridine-based monomer ligand. This work opens a new front of using CMP as an intriguing platform for developing highly efficient catalysts in controlling the regioselectivity in organic reactions.
Development of an air-stable, broadly applicable nickel source for nickel-catalyzed cross-coupling
Magano, Javier,Monfette, Sebastien
, p. 3120 - 3123 (2015/05/20)
The synthesis of NiCl(o-tolyl)(TMEDA) (3; TMEDA = tetramethylethylenediamine) and its application in coupling reactions is described. In combination with a suitable ligand, precatalyst 3 was applied to a wide range of transformations, such as Suzuki, amination, Kumada, Negishi, Heck, borylation, and reductive coupling. Yields of products obtained with 3 are equal or superior to those obtained with common Ni sources such as Ni(cod)2 (1) and NiCl2(dme) (2). Importantly, and unlike 1, complex 3 is stable for months in air as a solid, which eliminates the need for a glovebox and greatly facilitates the reaction setup. Thus, complex 3 is the first highly versatile Ni source that combines the broad applicability of 1 with the air stability of 2.
Nickel-catalyzed Mizoroki-Heck reaction of aryl sulfonates and chlorides with electronically unbiased terminal olefins: High selectivity for branched products
Tasker, Sarah Z.,Gutierrez, Alicia C.,Jamison, Timothy F.
, p. 1858 - 1861 (2014/03/21)
Achieving high selectivity in the Heck reaction of electronically unbiased alkenes has been a longstanding challenge. Using a nickel-catalyzed cationic Heck reaction, we were able to achieve excellent selectivity for branched products (≥19:1 in all cases) over a wide range of aryl electrophiles and aliphatic olefins. A bidentate ligand with a suitable bite angle and steric profile was key to obtaining high branched/linear selectivity, whereas the appropriate base suppressed alkene isomerization of the product. Although aryl triflates are traditionally used to access the cationic Heck pathway, we have shown that, by using triethylsilyl trifluoromethanesulfonate, we can effect a counterion exchange of the catalytic nickel complex, such that cheaper and more stable aryl chlorides, mesylates, tosylates, and sulfamates can be used to yield the same branched products with high selectivity. Branching out: A Ni-catalyzed Heck reaction for the preparation of 1,1-disubstituted alkenes is presented. High selectivity for the branched products is achieved with electronically unbiased aliphatic terminal olefins. Regioselectivities remain consistently high (≥19:1) throughout. TESOTf=triethylsilyl trifluoromethanesulfonate. Copyright
Regioselective Heck reaction of aliphatic olefins and aryl halides
Qin, Liena,Hirao, Hajime,Zhou, Jianrong
supporting information, p. 10236 - 10238 (2013/10/22)
A regioselective Heck reaction of aliphatic olefins and aryl bromides is realized at internal carbons of olefins. Methanol solvent promoted halide ionization from neutral arylpalladium halide complexes via hydrogen bonding, so as to create cationic aryl-Pd species for regioselective olefin insertion.
Intermolecular mizoroki-heck reaction of aliphatic olefins with high selectivity for substitution at the internal position
Qin, Liena,Ren, Xinfeng,Lu, Yunpeng,Li, Yongxin,Zhou, Jianrong
supporting information; experimental part, p. 5915 - 5919 (2012/07/30)
New ligand for old reaction: The title reaction of aryltriflates with aliphatic olefins leads to substitution at the internal position with high selectivity. The ratio of the desired isomer (shown in the scheme) to the sum of all other isomers is generall
Cobalt-catalyzed coupling of alkenyl triflates with aryl and alkenyl grignard reagents
Shirakawa, Eiji,Imazaki, Yusuke,Hayashi, Tamio
, p. 654 - 655 (2008/12/20)
Co(acac)3-PPh3 was found to effectively catalyze the C(sp2)-C(sp2) coupling of Grignard reagents to give alkenyl-arenes and conjugated dienes, utilizing close affinity towards alkenyl triflates. Copyright
