‘Proton sponge’ amides: unusual chemistry and conversion into superbasic 6,7-bis(dimethylamino)perimidines
摘要:
Starting from 1-acylamino-4,5-bis(dimethylamino)naphthalenes, the first representatives of previously unknown 6,7-bis(dimethylamino)perimidines have been synthesized. In accordance with the electron-donor nature of the heterocyclic rings in these compounds they behave as proton sponges, displaying higher basicity (pK(a) 8.4-93, DMSO) than those of the parent proton sponge (pK(a) 7.5, DMSO; 18.6, MeCN) and perimidine (pK(a) 13.6, MeCN). In accord with OFT calculations and proton transfer experiments, 1H-6,7-bis(dimethylamino)perimidines have been shown to exist as neutral rather than zwitterionic tautomers. A number of interesting observations concerning structure, synthesis, and reactivity of 1-acylamino-4,5-bis(dimethylamino)-8-nitronaphthalenes have been made. (C) 2012 Elsevier Ltd. All rights reserved.
‘Proton sponge’ amides: unusual chemistry and conversion into superbasic 6,7-bis(dimethylamino)perimidines
作者:Valery A. Ozeryanskii、Marina P. Vlasenko、Alexander F. Pozharskii
DOI:10.1016/j.tet.2012.12.040
日期:2013.2
Starting from 1-acylamino-4,5-bis(dimethylamino)naphthalenes, the first representatives of previously unknown 6,7-bis(dimethylamino)perimidines have been synthesized. In accordance with the electron-donor nature of the heterocyclic rings in these compounds they behave as proton sponges, displaying higher basicity (pK(a) 8.4-93, DMSO) than those of the parent proton sponge (pK(a) 7.5, DMSO; 18.6, MeCN) and perimidine (pK(a) 13.6, MeCN). In accord with OFT calculations and proton transfer experiments, 1H-6,7-bis(dimethylamino)perimidines have been shown to exist as neutral rather than zwitterionic tautomers. A number of interesting observations concerning structure, synthesis, and reactivity of 1-acylamino-4,5-bis(dimethylamino)-8-nitronaphthalenes have been made. (C) 2012 Elsevier Ltd. All rights reserved.