Pyridines metals

Several side reactions have also been observed, and, for the present purpose, all reactions leading to products other than 2,2 -bipyridines will be considered under this heading. Some of these undoubtedly involve hydrogen derived from the catalyst, but no attempt will be made adequately to review the field of reactions involving pyridines, metal catalysts, and hydrogen. 

Metal Pyridine Metal, Product Required Reaction... 

Polyhalogenated pyridines, metallation, 9, 23—24 Polyhalogenophenyl ligands, in platinum(II) complexes,... 

Homolytic substitution of pyridinium salts has scarcely been studied. The phenylation of pyridine in acetic acid solution by benzene-diazonium borofluoride has been reported,392 1 as has the phenylation of pyridine-metal complexes.3926... 

P. Tomasik and Z. Ratajewicz, Pyridine Metal Complexes , Chapter 4, Wiley-Interscience, New York (1985). 

Similarly to the analogous reaction with furo[2,3-Z>]pyridines, metallation of compound (20) with n-butyllithium in TMEDA followed by the addition of DMF afforded the 2-formyl derivative in 66% yield. Likewise, metallation of the isomer (22) under the same conditions afforded the 2-formyl derivative in comparable yield <84JHC785>. Introduction of a carbonyl group at C-3 of compound (20) was accomplished by halogen-metal exchange between 3-bromothieno[2,3-6]pyridine and n-butyllithium. Table 45 lists some of the thieno[2,3-Z>]pyridine derivatives formed by this method <74JHC355>. 

The heterobenzene ( -C5H5P)2Cr can be directly prepared by the metal-ligand vapor cocondensation technique. This heterocycle is aromatic and prefers ( -coordination to -coordination. For pyridine, cr-coordination via a lone pair is highly preferred over bonding that utihzes the tt-electron system. Therefore the direct synthesis of jj -pyridine metal complexes requires the N-atom to be blocked by means of substitution in the 2,6-positions ... 

Dipolar and non-dipolar pyridine metal complexes for nonlinear optics 00EJI229. 

The most rapid metal complexation reactions of porphyrins occur with two-valent metal ions. Metal ions of low electronegativity (Mg, Ca, Pb ri are introduced in refluxing pyridine, metal ions of intermediate electronegativity and... 

Double bonded ruthenium and osmium homodimers have been synthesized by Coil-man . These two metals are inserted into the porphyrin free base by using the corresponding metal chlorocarbonyl dimer [MCl2(CO)3]2- Irradiation of the resulting carbonyl metal(II) porphyrin irradiated in pyridine solutions yields the bis(pyridine) metal(II) porphyrin and leads to the expected dimers by heating under vacuum. This is shown in Scheme 16. 

A. R. Newkome, L. Strekowski, P. Tomasik, and Z. Ratajewicz, Pyridine - Metal Complexes. Part 6B, 1985. 

D. Y. Wu, M. Hayashi, S.H. Lin, and Z.Q. Tian, Theoretical Differential Raman Scattering Cross-Sections ofTotally-Symmetric Vibrational Modes of Free Pyridine and Pyridine-Metal Cluster Complexes, Spectrochimica Acta Part A... 

Figure 3 Strategies for the development of multinucleating ligands for use in coordination polymers based on pyridine metal-binding domains.

The reaction with pyridine is characteristic for compounds of CpjLnR series [161, 163, 171, 197]. The coordinating complex of (Mc5C5)2LnR(py) type, formed evidently at the initial stage, affords then the product of pyridine metallation ... 

The pyridine metallation as well as the mentioned above displacement of methane in Cp2LuMe by inert hydrocarbons like benzene testify the extremely high reactivity of rare earths. 

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