1758-62-9Relevant academic research and scientific papers
Rotational Lattice Vibrations of - and Pyrazine Crystals
Hieida, Toshikazu,Maehara, Masayoshi,Nibu, Yoshinori,Shimada, Hiroko,Shimada, Ryoichi
, p. 925 - 927 (1989)
Low-frequency Raman bands of the - and pyrazine crystals were studied at various temperatures between 4.2 and 300 K.All six rotational lattice vibrations were identified based on the isotopic factor (the ratio of the vibrational frquency of the - and pyrazine crystals) of the individual vibrations.Classification of the rotational lattice vibrations into symmetry species was made through the polarisation measurement of the Raman bands in single crystals.
Multiple Site Hydrogen Isotope Labelling of Pharmaceuticals
Chaudret, Bruno,Daniel-Bertrand, Marion,Derdau, Volker,Fazzini, Pier-Francesco,Feuillastre, Sophie,Garcia-Argote, Sébastien,Mustieles Marin, Irene,Palazzolo, Alberto,Pieters, Grégory,Tricard, Simon
, p. 21114 - 21120 (2020)
Radiolabelling is fundamental in drug discovery and development as it is mandatory for preclinical ADME studies and late-stage human clinical trials. Herein, a general, effective, and easy to implement method for the multiple site incorporation of deuterium and tritium atoms using the commercially available and air-stable iridium precatalyst [Ir(COD)(OMe)]2 is described. A large scope of pharmaceutically relevant substructures can be labelled using this method including pyridine, pyrazine, indole, carbazole, aniline, oxa-/thia-zoles, thiophene, but also electron-rich phenyl groups. The high functional group tolerance of the reaction is highlighted by the labelling of a wide range of complex pharmaceuticals, containing notably halogen or sulfur atoms and nitrile groups. The multiple site hydrogen isotope incorporation has been explained by the in situ formation of complementary catalytically active species: monometallic iridium complexes and iridium nanoparticles.
Ni(I)-X Complexes Bearing a Bulky α-Diimine Ligand: Synthesis, Structure, and Superior Catalytic Performance in the Hydrogen Isotope Exchange in Pharmaceuticals
Zarate, Cayetana,Yang, Haifeng,Bezdek, Máté J.,Hesk, David,Chirik, Paul J.
, p. 5034 - 5044 (2019)
The synthesis and spectroscopic characterization of a family of Ni-X (X = Cl, Br, I, H) complexes supported by the bulky α-diimine chelate N,N′-bis(1R,2R,3R,5S)-(-)-isopinocampheyl-2,3-butanediimine (ipcADI) are described. Diimine-supported, three-coordinate nickel(I)-X complexes have been proposed as key intermediates in a host of catalytic transformations such as C-C and C-heteroatom cross-coupling and C-H functionalization but have until now remained synthetically elusive. A combination of structural, spectroscopic, electrochemical, and computational studies were used to establish the electronic structure of each monomeric [(ipcADI)NiX] (X = Cl, Br, I) complex as a nickel(I) derivative supported by a redox-neutral α-diimine chelate. The dimeric nickel hydride, [(ipcADI)Ni(μ2-H)]2, was prepared and characterized by X-ray diffraction; however, magnetic measurements and 1H NMR spectroscopy support monomer formation at ambient temperature in THF solution. This nickel hydride was used as a precatalyst for the hydrogen isotope exchange (HIE) of C-H bonds in arenes and pharmaceuticals. By virtue of the multisite reactivity and high efficiency, the new nickel precatalyst provided unprecedented high specific activities (50-99 Ci/mmol) in radiolabeling, meeting the threshold required for radioligand binding assays. Use of air-stable and readily synthesized nickel precursor, [(ipcADI)NiBr2], broad functional group tolerance, and compatibility with polar protic solvents are additional assets of the nickel-catalyzed HIE method.
