Improved Synthesis of Polyazolylmethanes Under Solid-Liquid Phase-Transfer Catalysis

Synthesis, Structure and Reactivity of Ruthenium(II) Carbonyl Complexes Containing Bis(pyrazol‐1‐yl)methane and Bis(N‐methylimidazol‐2‐yl)methane

“…Ruthenium() trichloride hydrate was obtained from JohnsonϪMatthey, and used without purification. The ruthenium complex [Ru(CO) 2 Cl 2 ] n [36] and the ligands bis(pyrazol-1-yl)methane (BPM), [18] bis(3,5-dimethylpyrazol-1-yl)methane (dmBPM) [18] and bis(N-methylimidazol-1-yl)methane (BIM) [19] were prepared according to literature procedures. All solvents were degassed prior to use.…”

“…The NOESY showed a cis coordination of the chloride and carbonyl ligands, and this was confirmed by single crystal X-ray diffraction studies. The sp 2 -N donor poly(pyrazol-1-yl)methane and poly-(imidazol-2-yl)methane ligands, such as bis(pyrazol-1-yl)-methane (I) (BPM), [18] bis(3,5-dimethylpyrazol-1-yl)methane (II), [18] tris(pyrazol-1-yl)methane (III) (TPM), [18] bis(N-methylimidazol-2-yl)methane (IV) (BIM), [19] and tris(N-methylimidazol-2-yl)methanol (V; TIM) are neutral ligands closely related to the poly(pyrazolyl)borate ligands. [20] The basicity of the sp 2 -N donor atoms of the fivemembered heterocycles of BPM and BIM are considerably different to that of N-atoms of other ligands containing heterocycles, such as 2,2Ј-bipyridyl (BIPY), which has a significant effect on the relative degree of electron donation to the metal by the ligand.…”

Syntheses and characterisation of tris(3-(pyridin-2-yl)-1H-pyrazol-1-yl)methane and its bis(µ-hydroxo) dicobalt(II) complex

“…7,8 For the synthesis of the ligand tris(3-(pyridin-2-yl)-1H-pyrazol-1-yl)methane (HC(3-Pypz) 3 , 1) the substituted pyrazole 2-(1H-pyrazol-3-yl)pyridine 15 is used (Scheme 1a). With tetrabutylammoniumbromide as phase-transfer catalyst and sodium carbonate, we obtained the highest yields in this reaction.…”

Copper(II) complexes with a novel tris(3,5-diisopropyl-1-pyrazolyl)methane ligand, [Cu(X 2 ){HC(3,5- i Pr 2 pz) 3 }] (X Cl and NO 3 )

“…Trofimenko reported the syntheses of several tris(pyrazolyl)methane ligands and some transition metal compounds [4]. Recently, Elguero and co-workers [5], and Reger and co-workers [6] have developed improved procedures for the syntheses of these ligands. However, the introductions of any alkyl or aryl groups, which are more hindered than a methyl group, at the 5 position of its pyrazolyl ring have not been reported yet [6].…”