Stabille ϕ-komplexe - ein beitrag zum mechanismus der aromatenalkylierung

Highly conjugated architectures and labile reaction intermediates from coupling between 10π electron-deficient heteroaromatics andsym-trihydroxy- or triamino-benzene derivatives

“…The compounds Cl-DNBF and Cl-DNBZ have been reported to react with 2,4,6-trinitroaniline 21,22 and 1,3-diaminobenzenes, 23 but never with sym -triaminobenzenes 1–3. As described by the pioneering works of Effenberger, they have been coupled with a variety of electrophiles as proton, 24–32 halogens, 33,34 acyl-, 35–37 alkyl-, 38 and aryl-halides 39 giving Wheland complexes, whose high stability has been ascribed to the great ability of the three amino substituents to stabilize the positive charge on the carbocyclic ring. Recently, the coupling of triaminobenzenes with DNBF, 13 DNTP, 14 proton, 40 aryldiazonium salts, 41–45 trinitrothiophene 46 and chloro-nitrobenzofurazanes 47 produced novel intermediates of the aromatic substitution reaction, together, sometimes, with unexpected species.…”

New electron-donor and -acceptor architectures from benzofurazans and sym-triaminobenzenes: intermediates, products and an unusual nitro group shift

“…In the above reaction, as well as in the Michael-type addition to 1,2-diazabuta-1,3-dienes, 20 and in azo coupling with diazonium salts, [21][22][23] sym-triaminobenzenes 1-3 behave as carbon nucleophiles. On the contrary, with electrophiles such as protons 24,25 and alkyl halides, [26][27][28] they undergo an attack on both the aromatic carbon atom and the nitrogen atom of the amino substituent, to a relative extent, depending on the experimental conditions. It has been reported 29 that the reaction between 1-3 and halo-nitrobenzene derivatives gives, mainly under drastic reaction conditions, the corresponding biphenyls but, to the best of our knowledge, no literature report on heteroaryl halides has appeared so far.…”

Aryl diazonium salts and benzene derivatives bearing two electron-donor substituents: chemical and mechanistic behaviours

“…In particular, a class of compounds used for mechanistic studies is that of 1,3,5-tris(N,N-dialkylamino)-benzenes belonging to neutral aromatic substrates rich in electrons due to the presence of three electron-donating groups on the ring. These compounds are able to react as carbon nucleophiles with a plethora of electrophiles such as, halogens, 1,2 protons, and [3][4][5][6][7][8][9][10][11][12] alkyl-, 13 acyl-, [14][15][16] and aryl-halides. [17][18][19] Moreover, the reaction of 1,3,5-tris(N,N-dialkylamino)benzenes with charged 20 and neutral carbon electrophiles has recently been studied, providing interesting information on the relevant reaction intermediates.…”