A. S. Koch, Amy S. Feng, Traci A. Hopkins
Mar 1, 1993
Citations
0
Influential Citations
16
Citations
Journal
Journal of Organic Chemistry
Abstract
The reaction of 4-(dimethylamino)pyridine (DMAP) with hexachlorocyclopentadiene gives two products, 1,2,3,4,5-pentakis- (4-(dimethylamino)pyridinium-1-yl)cyclopentadienyl anion (1) and 1-chloro-2,3,4,5-tetrakis(4-(dimethylamino)pyridinium-1-yl)cyclopentadienyl anion (2). The pK a of the conjugate acid of 1, with protonation occurring on the cyclopentadienyl ring, is approximately -6. The reaction of DMAP witb hexafluorobenzene gives 1,2,4,5-tetrafluoro- 3,6-bis(4-(dimethylamino)-pyridinium-1-yl)benzene (3); its X-ray single crystal structure is presented. Upon further treatment of 3 with DMAP, 1-fluoro-2,3,4,5,6-pentakis(4-(dimethylamino)pyridinium-1-yl)benzene (4)is produced. The nucleophiles DMAP, 4-phenylpyridine, 1-methyl- imidazole, and 1-phenylimidazole were used with 1,2-dichlorotetrafluoro cyclobutene to produce respectively, 1,2-bis(4-(dimethylamino)pyridinium-1-yl)tetrafluorocyclobutene (5), 1,2-bis(4-phenylpyridinium-1-yl)tetrafluorocyclobutene (6), 1,2-bis(3-methylimidazolium-1-yl)tetrafluorocyclobutene (7), 1,2-bis(3-phenylimidazolium-1-yl)tetrafluorocyclobutene (8). The electrochemistry of some of these compounds is described