P. Carloni, E. Damiani, L. Greci
Jun 4, 1993
Citations
0
Influential Citations
8
Citations
Journal
Tetrahedron
Abstract
Abstract Quinolinic nitroxides 1a–c react with trichloro- (TCA) and trifluoro- (TFA) acetic acid to give dimers 3a–c and quinolines 4a–c as the main products. Products 3a–c are explained as arising via the intermediate formation of the radical cation 5 , which forms the final dimer through an oxidative dimerization promoted by the TCA or TFA. The formation of products 4a–c is explained by a Wagner-Meerwein type transposition of the phenyl group from C-2 to C-3. The disproportionation, which generally occurs in the presence of acid for nitroxides having the NO function conjugated with a π-system, has been excluded even though quinoneimine N-oxides 2a–c were isolated. The structure of compounds 3a and 4a were determined by crystal X-ray analysis.