65567-06-8Relevant articles and documents
Atypical and Asymmetric 1,3-P,N Ligands: Synthesis, Coordination and Catalytic Performance of Cycloiminophosphanes
Rong, Mark K.,Holtrop, Flip,Bobylev, Eduard O.,Nieger, Martin,Ehlers, Andreas W.,Slootweg, J. Chris,Lammertsma, Koop
supporting information, p. 14007 - 14016 (2021/09/09)
Novel seven-membered cyclic imine-based 1,3-P,N ligands were obtained by capturing a Beckmann nitrilium ion intermediate generated in situ from cyclohexanone with benzotriazole, and then displacing it by a secondary phosphane under triflic acid promotion. These “cycloiminophosphanes” possess flexible non-isomerizable tetrahydroazepine rings with a high basicity; this sets them apart from previously reported iminophophanes. The donor strength of the ligands was investigated by using their P-κ1- and P,N-κ2-tungsten(0) carbonyl complexes, by determining the IR frequency of the trans-CO ligands. Complexes with [RhCp*Cl2]2 demonstrated the hemilability of the ligands, giving a dynamic equilibrium of κ1 and κ2 species; treatment with AgOTf gives full conversion to the κ2 complex. The potential for catalysis was shown in the RuII-catalyzed, solvent-free hydration of benzonitrile and the RuII- and IrI-catalyzed transfer hydrogenation of cyclohexanone in isopropanol. Finally, to enable access to asymmetric catalysts, chiral cycloiminophosphanes were prepared from l-menthone, as well as their P,N-κ2-RhIII and a P-κ1-RuII complexes.
A Palladium-Free Sonogashira Coupling Protocol Employing an in Situ Prepared Copper/Chelating 1,2,3-Triazolylidene System
Tonis, Efstathios,Stein, Felix,Stamatopoulos, Ioannis K.,Stubbe, Jessica,Zarkadoulas, Athanasios,Sarkar, Biprajit,Vougioukalakis, Georgios C.
supporting information, p. 616 - 620 (2020/11/25)
A new, palladium-free Sonogashira coupling reaction protocol using a catalytic system that comprises a simple, cheap, widely available copper salt and a chelating 1,2,3-triazolylidene ligand precursor is reported. This protocol provides the desired coupling products in moderate to very good yields.
Synthesis, structural and toxicological investigations of quarternary phosphonium salts containing the P-bonded bioisosteric CH2F moiety
Dubovnik, Sviatlana,Karaghiosoff, Konstantin,Kornath, Andreas,Reichel, Marco,Roidl, Andreas,Unger, Cornelia
, p. 14306 - 14315 (2020/09/03)
Tertiary alkyl, aryl or amino phosphines PR3 (R = Me, nBu, C2H4CN, NEt2) and the bis[(2-diphenylphosphino)phenyl]ether (POP) were allowed to react with fluoroiodomethane to produce fluoromethyl phosphonium salts in yields between 60-99%. The compounds were characterized by vibrational and NMR spectroscopy and in most cases also by single crystal X-ray diffraction. Diphenyl(fluoromethyl) phosphine was synthesized as a mixed aryl-alkyl-phosphine and the TEP value (Tolman electronic parameter) was determined in order to explain its low reactivity. The molecular and crystal structures of the new fluoromethyl phosphonium salts [R3PCH2F]I with R = Me, C2H2CN and NEt2 as well as of the salt resulting from the fluoromethylation of POP provided additional information on the structural behavior of the bioisoster CH2F group bonded to phosphorus. Hydrogen bonding in the crystal is compared with that observed in the crystal structure of PPh3CH2FI. The toxicity of the sufficiently water soluble salt [Me3PCH2F]I was investigated and the toxicological effect of the CH2F group was compared to that of the bioisoster CH2OH group in THPS. This journal is
