Azaaromatics

Some recent general reviews deal with the mechanism of N-nitrosation in aqueous solution (345), the nitrosation of secondary amines (346). the effect of solvent acidity On diazotization (347) and the reactivity of diazonium salts (1691). Therefore, a complete rationalization of the reactivity of amino azaaromatics would be timelv. 

Linear relationships have been established on one hand between the Rf and pAa values of these azaaromatic bases (in the absence of steric hindrance of the ring nitrogen) and on the other hand, between the... 

Quantum chemical predictions of tautomeric equilibria Ab initio multireference Cl studies of tautomers UPS spectra Combined approach to the tautomerism in azaaromatic heterocycles by N, C, and H NMR Fluoro-azoles Experimental data and MNDO studies Tautomerism A review... 

Cyclization reactions of quaternary salts of azaaromatic compounds 97KGS23. 

The triplet nitrenium ion, however, lacks symmetry but, unlike the excited triplet states of other azaaromatic systems such as pyridine, is surprisingly planar.283 Theoretical dipole moments for cyclopent[c]- and cyclopent[rf]azepine, and the molecular geometry of cyclopent[rf]-azepine, have been calculated using semiempirical ab initio methods.3... 

Azaaromatics can be perfluoroalkylated selectively in the 2-position using RLi-BF3 in a Ziegler-Zeisser-type reaction. The BF3 was essential as a promoter and other Lewis acids were found to be less effective. 

B. General Reactions of Azaaromatics with Organometallic Reagents and... 

BCJ3785). Furthermore, 2-bromopyridine and related azaaromatics have been reported to react with allyl Grignard reagents to initially form complex 23 between the pyridyl nitrogen atom and the Grignard reagent. 

As shown in the previous sections, pyridine and related azaaromatic compounds possess a strong electron-withdrawing property equivalent to thep-nitrophenyl group and hence serve as good leaving groups. The facile... 

The chemistry of both organic sulfur compounds and azaaromatic compounds has been widely investigated mainly for industrial purposes for many years, and vast amounts of data have been accumulated. However, many studies lack mechanistic support. 

There are three classical methods for the synthesis of the 1,2,5-thiadiazole ring system. They are characterized by the combination of atom fragments necessary to form the ring [4 + 1], [3 + 2] (type A), and [3 + 2] (type B) (Figure 3). These methods will be reviewed in the subsequent sections (Sections 4.09.9.1.1 and 4.09.9.1.2). The synthesis of aromatic and azaaromatic fused 1,2,5-thia-diazole has been reviewed <83H(20)7l). 

Directed Metalation of Pi-Deficient Azaaromatics Strategies of Functionalization of Pyridines,... 

---