92-53-5Relevant articles and documents
Product inhibition in nucleophilic aromatic substitution through DPPPent-supported π-arene catalysis
Mueller, Benjamin R. J.,Schley, Nathan D.
, p. 10114 - 10119 (2020)
Nucleophilic aromatic substitution (SNAr) of fluorobenzene by morpholine at a bis(diphenylphosphino)pentane-supported ruthenim complex is investigated as a model system for π-arene catalysis through the synthesis and full characterization of proposed intermediates. The SNAr step proceeds quickly at room temperature, however the product N-phenylmorpholine binds tightly to the ruthenium ion. In the case examined, the thermodynamics of arene binding favor product N-phenylmorpholine over fluorobenzene binding by a factor of 2000, corresponding to significant product inhibition. Observations of the catalyst resting state support this hypothesis and demonstrate an additive-controlled role for a previously-proposed ligand cyclometalation. This journal is
Palladium complexes of o-xylylene-linked alkoxybenzimidazolin-2-ylidenes containing aryl N-substituents: Examples of C-H activation and the formation of a tri-nuclear palladium complex
Simpson, Peter V.,Brown, David H.,Skelton, Brian W.,White, Allan H.,Baker, Murray V.
, p. 79 - 91 (2015)
Palladium complexes of new bidentate N-heterocyclic carbene (NHC) incorporating benzimidazolin- 2-ylidene units have been synthesized and structurally and spectroscopically characterised. The NHC ligands are furnished with aryl substituents on the nitroge
Product selective reaction controlled by the combination of palladium nanoparticles, continuous microwave irradiation, and a co-existing solid; ligand-free Buchwald-Hartwig aminationvs.aryne amination
Akiyama, Toshiki,Arai, Masayoshi,Arisawa, Mitsuhiro,Haneoka, Hitoshi,Harada, Kazuo,Murai, Kenichi,Murakami, Yosuke,Ohki, Yuuta,Ohta, Ryousuke,Sako, Makoto,Sirimangkalakitti, Natchanun,Suzuki, Takeyuki,Takahashi, Naoyuki,Takehara, Tsunayoshi,Yamada, Makito
supporting information, p. 8131 - 8137 (2021/10/29)
We have developed a continuous microwave irradiation-assisted Buchwald-Hartwig amination using our original Pd nanoparticle catalyst with a copper plate as a co-existing metal solid. In this methodology, a microwave-controlled product selectivity was achieved between Buchwald-Hartwig amination and aryne amination performed under strongly basic conditions and at a high reaction temperature, because a polar chemical species such as Ar-Pd-halogen might be activated selectively by microwave radiation. Moreover, our catalyst could be used repeatedly over 10 times, and the amount of Pd leaching could be suppressed to a low level.
Effect of Precatalyst Oxidation State in C-N Cross-Couplings with 2-Phosphinoimidazole-Derived Bimetallic Pd(I) and Pd(II) Complexes
Martinez, Erin E.,Moreno, Mariur Rodriguez,Barksdale, Caleb A.,Michaelis, David J.
supporting information, p. 2763 - 2767 (2021/08/27)
We report the catalytic activity of two phosphinoimidazole-derived bimetallic palladium complexes in Pd-catalyzed amination reactions. Our studies demonstrate that the starting oxidation state (Pd(I) or Pd(II)) of the dimeric complex has a significant effect on the efficiency of the catalytic reaction. The corresponding Pd(I) complex shows higher reactivity in Buchwald-Hartwig aminations, while the Pd(II) complex is much more reactive in carbonylative amination reactions. These new dimeric palladium complexes provide good to excellent reactivity and yields in the amination reactions tested.