Structure analog studies

Heterocyclic structures analogous to the intermediate complex result from azinium derivatives and amines, hydroxide or alkoxides, or Grignard reagents from quinazoline and orgahometallics, cyanide, bisulfite, etc. from various heterocycles with amide ion, metal hydrides,or lithium alkyls from A-acylazinium compounds and cyanide ion (Reissert compounds) many other examples are known. Factors favorable to nucleophilic addition rather than substitution reactions have been discussed by Albert, who has studied examples of easy covalent hydration of heterocycles. 

Thompson, J. A. Carlson, T. J. Sun, Y. Dwyer-Nield, L. D. Malkinson, A. M. Studies using structural analogs and inbred strain differences to support a role for quinone methide metabolites of butylated hydroxytoluene (BHT) in mouse lung tumor promotion. Toxicology 2001, 160, 197-205. 

Studies of the thermodynamics of formation of complexes of zinc with 2,2 -bipyridine in the presence of halide and thiocyanate ions in DMF has been carried out.205 The zinc complexes of 2,2 -bipyridine with A-(benzenesulfonyl)glycine and A-(toluene- -sulfonyl)glycine were synthesized and infrared data implied a structural analogy with the cadmium complexes. This suggests that the zinc promotes sulfonamide nitrogen deprotonation in the amino acid ligands in the solid state.206... 

R. E. McCarley No, we have done very little work along this line, although I think important results will be obtained from studies of mixed 0, S phases. So far we have found no direct structural analogies between the reduced ternary molybdenum oxide phases and the various ternary sulfide or selenide phases of the Chevrel type. 

A heteroleptic zirconium sandwich complex in which Zr links octaethylporphyrazine (28) and the structurally analogous octa-ethylporphyrin has also been reported. To spectroscopically study the... 

This introduction brings us back to the structural analogy shown earlier between the cation 1 dehydrocyclization reaction and the plausible connection between this reaction and that for a 2-octyl cation intermediate 3 (and which could include many other linear alkane carbocation systems with at least six contiguous carbons). Our initial aim therefore was to study computationally the dehydrocyclization of the cyclodecyl cation 1, to see if one could satisfactorily model this known reaction. 

For the purpose of this discussion, styrene and pyridine may be considered to be structurally analogous since the aromatic ring of styrene is complemented by the electron rich -CH=CH2 group whilst pyridine has the nitrogen lone pair. Acid effects observed in the pyridine-methanol system may thus be extrapolated to styrene-methanol. In separate studies, it has been shown that inclusion of acid increased the quantities of scavenging products, pyridyl methanol and methylpyridine. In addition, one scavenging product, pyridylethanol, disappeared and was replaced by a number of unidentified products when acid was included in the radiolysis... 

Analogous studies on the dimerization of cyclopentadiene in water revealed a stabilization of the transition structure relative to the initial structure as a result of a difference in... 

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