2-α-Hydroxyalkyl- and 2,7-Di(α-hydroxyalkyl)-1,8-bis(dimethylamino)naphthalenes: Stabilization of Nonconventional In/Out Conformers of “Proton Sponges” via N···H−O Intramolecular Hydrogen Bonding. A Remarkable Kind of Tandem Nitrogen Inversion
摘要:
A regular set of 2-(alpha-hydroxymethyl)- and 2,7-di(alpha-hydroxymethyl)-1,8-bis(dimethylamino)naphthalenes has been prepared. Their X-ray, NMR, and IR studies have demonstrated that in tertiary mono-alcohols the orientation of free nitrogen electron pairs in crystals and solution corresponds to nonconventional in/out conformers stabilized by O-H center dot center dot center dot N intramolecular hydrogen bonding. For tertiary 2,7-dialcohols, the superimposed equilibrating in/out-out/in nitrogen invertomers are observed in solution. Unlike this, primary and secondary mono- and dialcohols commonly exist in the in/in form, which is typical for the parent proton sponge and the majority of its derivatives.
ortho-Ketimines of 1,8-Bis(dimethylamino)naphthalene: Synthesis, Hydrolytic Stability and Transfer of Basicity from Proton Sponge Moiety to the Imino Function
important of which is a strong electron-donor effect of peri-dimethylamino groups. A series of 2-ketimines and 2,7-diketimines of 1,8-bis(dimethylamino)naphthalene (proton sponge, DMAN) have been obtained and converted into the corresponding ketones via acidic hydrolysis. Investigation of structural and spectral properties of DMAN-based imines led to the conclusion that their unusual hydrolytic stability results
Tandem Synthesis of 10-Dimethylaminobenzo[<i>h</i>]quinazolines from 2-Ketimino-1,8-bis(dimethylamino)naphthalenes via Nucleophilic Replacement of the Unactivated Aromatic NMe<sub>2</sub> Group
作者:Vladimir Y. Mikshiev、Alexander S. Antonov、Alexander F. Pozharskii
DOI:10.1021/acs.orglett.6b01178
日期:2016.6.17
a result of [2 + 2 + 2] nucleophilic cascade annulation produces 10-dimethylaminobenzo[h]quinazolines, as yet unknown NMe2/–N═ analogues of the proton sponge. It is even more convenient to use preliminarily prepared 2-ketimino-1,8-bis(dimethylamino)naphthalenes as starting material. The substitution of both peri-NMe2 groups furnishing quinazolino[7,8-h]quinazoline derivatives is also possible. The process
Organometallic Synthesis, Molecular Structure, and Coloration of 2,7-Disubstituted 1,8-Bis(dimethylamino)naphthalenes. How Significant Is the Influence of “Buttressing Effect” on Their Basicity?
作者:Alexander F. Pozharskii、Oksana V. Ryabtsova、Valery A. Ozeryanskii、Alexander V. Degtyarev、Olga N. Kazheva、Gregory G. Alexandrov、Oleg A. Dyachenko
DOI:10.1021/jo035350t
日期:2003.12.1
On treatment of 2,7-dilithio- (6a) and 2,7-bis(bromomagnesio)- (6b) naphthalenes with a number of electrophiles, new "proton sponge" derivatives 7a-e,g, containing iodo, methylthio, trimethylsilyl, methyl, n-butyl, and ethoxycarbonyl groups in ortho-positions to dimethylamino groups, have been synthesized. The investigation of their molecularstructure, spectral characteristics, and basicity reveals
Aggregation Behavior of Lithionaphthalenes in Solution: Experimental and Theoretical Study
作者:Alexander S. Antonov、Valerii V. Karpov、Elena Yu. Tupikina、Peter M. Tolstoy、Mikhail A. Vovk
DOI:10.1021/acs.organomet.0c00524
日期:2020.10.26
The aggregation of a series of mono- and dilithionaphthalenes in THF solutions in the presence of tetramethylethylenediamine (TMEDA) and pentamethyldiethylenetriamine (PMDTA) was studied by NMR spectroscopy and quantum chemical calculations. The stability of dimeric species in diluted solutions as well as reasons of their disaggregation in some cases has been discussed. For the lithioderivatives of
The action of 2-, 3-, and 4-pyridinecarboxaldehydes on 1,8-bis(dimethylamino)-2-lithium-and 1,8-bis(dimethylamino)-2,7-dilithiumnaphthalenes gave secondary mono-and dicarbinols containing pyridylcarbinol groups at C-2 and C-7 of the proton sponge. Spectral and X-ray diffraction structural data were used to study the molecular structure of these products.