N-1,N-10-Ethyleneisoalloxazinium chloride and its 8-Cl-, 7-CF3-, and 3-CH3-
7-CF3-substituted analogs were synthesized for the purpose of exhibiting th
ermal reactivity with organic substrates. The new flavins were characterize
d spectroscopically and electrochemically, and were found to react with ami
nes, thiols, and phenylhydrazine, the latter case exhibiting catalytic aero
bic recycling. Reactions of aliphatic benzylic and cyclopropyl amines with
the 7-CF3 analog were also compared to their oxidations by tris(phenanthrol
ine)iron(III). All reactions of the flavinium salts appear to occur through
heterolytic rather than homolytic mechanisms. (C) 2001 Elsevier Science Lt
d. All rights reserved.