N. V. Vistorobskii

peri-Naphthylenediamines. 36. 5,6-Bis(dimethylamino)acenaphthylene in [4+2] cycloaddition reactions. Synthesis and characteristic features of protonation of “proton sponges” with the 8,9-diazafluoranthene structure

Abstract5,6-Bis(dimethylamino)acenaphthylene is readily involved in [4+2] cycloaddition reactions with symm-tetrazine derivatives to form new “proton sponges” with the diazafluoranthene skeleton. Under analogous condition, 1,8-bis(dimethylamino)-4-vinylnaphthalene gave 4-pyridazinyl derivatives. The relative reactivities of 5,6-bis(dimethylamino)acenaphthylene, 1,8-bis(dimethylamino)-4-vinylnaphthalene, 5-dimethylaminoacenaphthylene, and acenaphthylene in the reactions with 3,6-diphenyl-symm-tetrazine are in a ratio of 32 : 17 : 14 : 1. The site of protonation of 3,4-bis(dimethylamino)-7,10-diphenyl-8,9-diazafluoranthene is controlled by the basicity of the solvent. The reaction in acetonitrile afforded the cation stabilized by an intramolecular hydrogen bond, whereas the reaction in dimethyl sulfoxide gave rise to the resonance-stabilized cation. 6,7-Bis(dimethylamino)phenalen-1-one was protonated only at the carbonyl group.

peri-naphthylenediamines: 28. Nitration of 1,8-bis(dimethylamino)naphthalene and 5,6-bis(dimethylamino)acenaphthene in neutral and weakly acidic media. The first case of isolation ofo-nitro ando,o′-dinitro derivatives of “proton sponges”

Abstracto-Nitro ando,o′-dinitro derivatives of 1,8-bis(dimethylamino)naphthalene and its acenaphthene analog were prepared for the first time by direct nitration with nitrogen dioxide or tetranitromethane. When 5,6-bis(dimethylamino)acenaphthene was treated with nitric acid in AcOH or MeCN or with nitronium tetrafluoroborate in MeCN, nitration was accompanied by partial demethylation of one of the NMe2 groups.

HETEROCYCLIC ANALOGS OF PLEIADIENE. 67. FORMYLATION OF PERIMIDONES, 2,3-DIHYDROPERIMIDINES, AND PERIMIDINES

Vilsmeier formylation of 1,3-dialkylperimidones, 1,3-dialkyl-2,3-dihydroperimidines, and 2-trifluoromethyl-perimidines is performed. The1H NMR spectra of the resulting mono- and dialdehydes are discussed.

peri-Naphthylenediamines: 27. Transformations of tertiary carbocations stabilized by the 4,5-bis(dimethylamino)-1-naphthyl group

Tertiary alcohols containing the 4,5-bis(dimethylamino)-1-naphthyl group were synthesized. The carbocations that formed from α-methyl-containing alcohols in an acidic medium underwent smooth El elimination to give the corresponding unsaturated derivatives of the “proton sponge” in good yields. At the same time, the carbocation generated from 4-(α-hydroxybenzhydryl)-1,8-bis(dimethylamino)naphthalene was converted into a benzo-[a]fluorene derivative as a result of a complex reaction which has been previously unknown in the chemistry of “proton sponges.” The structure of the latter derivative was established by X-ray diffraction analysis.

peri-Naphthylenediamines: XL. Solvatochromism of 1-methyl-4-[2-(1-naphthyl)ethenyl]pyridinium salts, including that containing “proton sponge” residue

A number of 1-methyl-4-[2-(1-naphthyl)ethenyl]pyridinium salts were synthesized by condensation of 1,4-dimethylpyridinium iodide with naphthalene-1-carbaldehydes containing dimethylamino groups in positions 4 and 5. The obtained salts are characterized by negative solvatochromism which is the most pronounced for those possessing 1,8-bis(dimethylamino)naphthalene (“proton sponge”) and 1,2,2,3-tetramethyl-2,3-dihydroperimidine residues.

PERI-NAPHTHYLENEDIAMINES. 19. ACID-CATALYZED TRANSFORMATIONS OF 4,5-BIS(DIALKYLAMINO)-1-HYDROXYMETHYINAPHTHALENES

The action of concentrated HCl on 4,5-bis(diethylamino)-1-hydroxymethylnaphthalene resulted in its cyclodimerization of the “head-to-head” type to form a spiro-compound, but, unlike its 4,5-bis(dimethylamino)-analog, cyclodimerization products did not occur on Al2O3. The transformation of 4,5-bis(dimethylamino)-1-hydroxymethylnaphthalene on Al2O3, TiO2, and SiO2 afforded the previously unknown di[4,5-bis(dimethylamino)naphthyl-4]methane, a spiro-compound of the “head-to-tail” type. 4,5-Bis(diethylamino)-1-hydroxy-methylnaphthalene and 4,5-bis(diethylamino)naphthalene-1-carbaldehyde were synthesized.

Resonance-stabilized α-naphthylmethyl carbocations and spiro compounds based thereon: VII. Transformations of α-naphthylmethyl carbocations stabilized by one electron-donor group or peri-fused heteroring

Abstract1-Hydroxymethyl-and 1-alkoxymethylnaphthalenes containing dimethylamino and methoxy groups or a heteroring in positions 4 and 5 react with protic and Lewis acids to give 1-naphthylmethyl carbocations. Reactions of the latter with the initial alcohol molecule lead to the formation of oligomerization or dehydrogenation (to aldehyde) products or the corresponding dinaphthylmethanes. In some cases, the process was accompanied by cyclodimerization to form cyclohexadienone spiro derivatives in a small yield.