ChemInform Abstract: Electron-Transfer-Induced Photocyclization Reactions of Arene-Iminium Salt Systems. Effects of Cation Diradical Deprotonation and Desilylation on the Nature and Efficiencies of Reaction Pathways Followed.

ChemInform Abstract

The photocyclization of (Ia) to give (IV) is concluded to proceed exclusively via a mechanism including sequential electron transfer-desilylation. This is in accord with a rapid conversion of the cation radical (II) to the neutral radical (III) by desilylation. In the case of (Ib), (V) results from the homolytic fragmentation of (II). Varying the temp., (Ia) can be converted selectively to (V) or(IV). A dipolar cyclization is responsible for the fluoride-induced formation of (V).