1717-82-4Relevant academic research and scientific papers
Accelerating palladium-catalyzed C-F bond formation: Use of a microflow packed-bed reactor
Noel, Timothy,Maimone, Thomas J.,Buchwald, Stephen L.
, p. 8900 - 8903 (2011)
A flow process for Pd-catalyzed C-F bond formation is described. A microreactor with a packed-bed design allows for easy handling of large quantities of insoluble CsF with precise control over reaction times, efficient mixing, and the ability to safely handle elevated temperatures and pressures. A variety of aryl triflates, including heteroaryl ones, were converted into aryl fluorides in short reaction times (see scheme).
Studying regioisomer formation in the pd-catalyzed fluorination of aryl triflates by deuterium labeling
Milner, Phillip J.,Kinzel, Tom,Zhang, Yong,Buchwald, Stephen L.
supporting information, p. 15757 - 15766 (2015/02/02)
Isotopic labeling has been used to determine that a portion of the desired product in the Pd-catalyzed fluorination of electron-rich, non-ortho-substituted aryl triflates results from direct C-F cross-coupling. In some cases, formation of a Pd-aryne intermediate is responsible for producing undesired regioisomers. The generation of the Pd-aryne intermediate occurs primarily via ortho-deprotonation of a L·Pd(Ar)OTf (L = biaryl monophosphine) species by CsF and thus competes directly with the transmetalation step of the catalytic cycle. Deuterium labeling studies were conducted with a variety of aryl triflates.
Phosphine-Ligated Palladium Sulfonate Palladacycles
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Paragraph 0059; 0301, (2014/01/08)
Described are palladium precatalysts, and methods of making and using them. The palladium precatalysts show improved stability and improved reactivity in comparison to previously-described palladium precatalysts.
A comprehensive study of the effects of spectator ligands, transition metals and lithium halide additives on the efficiency of iron, nickel and palladium-catalyzed cross-coupling reactions of cyclohexyl magnesium bromide with fluorinated bromobenzenes
Dahadha, Adnan,Imhof, Wolfgang
, p. 200 - 216 (2013/10/21)
Thirteen mono-, bis- and trifluorinated bromobenzene derivatives have been coupled with cyclohexyl magnesium bromide or the corresponding lithiumchloride or lithiumbromide adducts. Iron, nickel and palladium complexes of the general formula [MCl2(dppx)] (x = (CH2)n, n = 1, 2, 3) have been used as the precatalysts. Palladium based catalysts give high yields of the coupling product with the Grignard reagent itself whereas lithium halides are needed as additives to achieve comparable efficiencies if nickel and iron catalysts are used. Yields also depend on the chain length of the bridging units and on the fact whether fluorine substituents are present in ortho position with respect to bromine.
Nickel-mediated oxidative fluorination for PET with aqueous [ 18F] fluoride
Lee, Eunsung,Hooker, Jacob M.,Ritter, Tobias
, p. 17456 - 17458 (2013/01/15)
A one-step oxidative fluorination for carbon-fluorine bond formation from well-defined nickel complexes with oxidant and aqueous fluoride is presented, which enables a straightforward and practical 18F late-stage fluorination of complex small molecules with potential for PET imaging.
