459868-21-4Relevant academic research and scientific papers
Evidence for single-electron pathways in the reaction between palladium(II) dialkyl complexes and alkyl bromides under thermal and photoinduced conditions
Andersen, Thomas L.,Kramer, S?ren,Overgaard, Jacob,Skrydstrup, Troels
, p. 2058 - 2066 (2017)
Palladium(II) dialkyl complexes have previously been studied for their formation of alkanes through reductive elimination. More recently, these complexes, especially L2Pd(CH2TMS)2 derived from Pd(COD)(CH2TMS)2, have found general use as palladium(0) precursors for stoichiometric formation of oxidative addition complexes through a two-electron reductive elimination/oxidative addition sequence. Herein, we report evidence for an alternative pathway, proceeding through single-electron elementary steps, when DPEPhosPd(CH2TMS)2 is treated with an α-bromo-α,α-difluoroacetamide. This new pathway does not take place through a palladium(0) intermediate, neither does it afford the expected oxidative addition complexes. Instead, stoichiometric amounts of carbon-centered alkyl radicals are formed, which can be trapped in high yields either by TEMPO or by an arene, leading to α-aryl-α,α-difluoroacetamides. The same overall transformation takes place under both thermal conditions (70 °C) and irradiation with a household light bulb (at 30 °C). It is also demonstrated that DPEPhosPdMe2, made in situ from Pd(TMEDA)Me2, displays a similar initial reactivity. Finally, electronically and structurally different alkyl bromides were evaluated as reaction partners.
The coordination behaviour of large natural bite angle diphosphine ligands towards methyl and 4-cyanophenylpalladium(II) complexes
Zuideveld, Martin A.,Swennenhuis, Bert H. G.,Boele, Maarten D. K.,Guari, Yannick,Van Strijdonck, Gino P. F.,Reek, Joost N. H.,Kamer, Paul C. J.,Goubitz, Kees,Fraanje, Jan,Lutz, Martin,Spek, Anthony L.,Van Leeuwen, Piet W. N. M.
, p. 2308 - 2317 (2007/10/03)
The structures of neutral and ionic 4-cyanophenylpalladium(II) and methylpalladium(II) complexes containing bidentate phosphine ligands were investigated in solution and in the solid state. Diphosphine ligands with a xanthene and a ferrocene backbone were used. New bis(dialkylphosphino) substituted Xantphos ligands were synthesised. 1H NMR and 31P NMR spectroscopy, conductivity measurements, UV-Vis spectroscopy, and X-ray crystallography were used to elucidate the structures of the complexes. Subtle changes of the phosphine ligands govern the coordination mode of the ligand. A variety of bidentate cis-, and trans-coordination and terdentate P-O-P, P-S-P and P-Fe-P coordination modes of the ligands were observed.
