935552-89-9Relevant academic research and scientific papers
The site-selectivity and mechanism of Pd-catalyzed C(sp2)-H arylation of simple arenes
Kim, Daeun,Choi, Geunho,Kim, Weonjeong,Kim, Dongwook,Kang, Youn K.,Hong, Soon Hyeok
, p. 363 - 373 (2021/01/14)
Control over site-selectivity is a critical challenge for practical application of catalytic C-H functionalization reactions in organic synthesis. Despite the seminal breakthrough of the Pd-catalyzed C(sp2)-H arylation of simple arenes via a concerted metalation-deprotonation (CMD) pathway in 2006, understanding the site-selectivity of the reaction still remains elusive. Here, we have comprehensively investigated the scope, site-selectivity, and mechanism of the Pd-catalyzed direct C-H arylation reaction of simple arenes. Counterintuitively, electron-rich arenes preferably undergo meta-arylation without the need for a specifically designed directing group, whereas electron-deficient arenes bearing fluoro or cyano groups exhibit high ortho-selectivity and electron-deficient arenes bearing bulky electron-withdrawing groups favor the meta-product. Comprehensive mechanistic investigations through a combination of kinetic measurements and stoichiometric experiments using arylpalladium complexes have revealed that the Pd-based catalytic system works via a cooperative bimetallic mechanism, not the originally proposed monometallic CMD mechanism, regardless of the presence of a strongly coordinating L-type ligand. Notably, the transmetalation step, which is influenced by a potassium cation, is suggested as the selectivity-determining step.
Method for synthesizing biphenyl compound by taking phenol as raw material
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Paragraph 0068-0070, (2020/07/15)
The invention discloses a method for synthesizing a biphenyl compound by using phenol as a raw material in the technical field of organic chemical synthesis, which comprises the following steps: carrying out a mixed reaction process on phenol or substituted phenol, alkali and 50-90% ethanol aqueous solution, slowly introducing sulfonyl fluoride gas, and carrying out magnetic stirring reaction at normal temperature for 4-12 hours, adding arylboronic acid, alkali and a palladium catalyst into a round-bottom flask, continuing to react for 6-12 hours at normal temperature, after the reaction is finished, adding a saturated edible salt solution into the round-bottom flask, carrying out a water quenching reaction process to obtain a reaction mixture, extracting a reaction product from the reaction mixture by using ethyl acetate, combining organic phases, concentrating filtrate, and separating the concentrated filtrate by using column chromatography to obtain analytically pure biphenyl or terphenyl compounds. By using the method, on one hand, the production cost of the biphenyl compound is reduced, and on the other hand, the method also has a wide application prospect in the aspects of synthesis of natural products, medicines, pesticides, herbicides, polymer conduction materials, liquid crystal materials and the like.
A one-pot, single-solvent process for tandem, catalyzed C-H borylation-Suzuki-Miyaura cross-coupling sequences
Harrisson, Peter,Morris, James,Steel, Patrick G.,Marder, Todd B.
experimental part, p. 147 - 150 (2009/05/30)
Methyl tert-butyl ether is a suitable solvent for iridium-catalyzed C-H borylation followed, in the same pot, by palladium-catalyzed Suzuki-Miyaura cross-coupling sequences, giving high yields of biaryls. Georg Thieme Verlag Stuttgart.
Copper + nickel-in-charcoal (Cu-Ni/C): A bimetallic, heterogeneous catalyst for cross-couplings
Lipshutz, Bruce H.,Nihan, Danielle M.,Vinogradova, Ekaterina,Taft, Benjamin R.,Boskovic, Zarko V.
supporting information; experimental part, p. 4279 - 4282 (2009/05/30)
(Chemical Equation Presented) A new heterogeneous catalyst composed of copper and nickel oxide particles supported within charcoal has been developed. It catalyzes cross-couplings that traditionally use palladium, nickel, or copper, including Suzuki-Miyaura reactions, Buchwald-Hartwig aminations, vinylalane alkylations, etherifications of aryl halides, aryl halide reductions, asymmetric conjugate reductions of activated olefins, and azide-alkyne "click" reactions.
Pd-catalyzed Kumada-Corriu cross-coupling reactions at low temperatures allow the use of Knochel-type Grignard reagents
Martin, Ruben,Buchwald, Stephen L.
, p. 3844 - 3845 (2008/02/02)
A catalyst system able to operate at temperatures as low as -65 °C for the Pd-catalyzed Kumada-Corriu cross-coupling reaction is described. This unprecedented level of activity allows the use of highly functionalized (Knochel-type) Grignard reagents. Additionally, the tolerance of the protocol toward a wide variety of functional groups allows for the synthesis of valuable compounds, including heterocyclic or polyfluoro biaryls. Copyright
