The authors' studies in the area of phthalimide photochemistry are discusse
d in the context of the development of new methods for N-heterocycle synthe
sis. Emphasis is given to reactions which are initiated by both intermolecu
lar and intramolecular SET from silicon-containing electron donors to excit
ed states of phthalimides and related maleimides and conjugated imides. The
photoaddition and photo cyclization processes which ensue follow mechanist
ic pathways, in which efficient desilylation of initially formed radical ca
tion occurs to generate radical pair and biradical intermediates that serve
as precursors of the products. Several examples that demonstrate the prepa
rative potential of these reactions axe presented. These are taken from the
authors' investigations of (1) phthalimido-alkylsilane photocyclization re
actions, (2) azomethine ylide-forming excited-state processes of N-(trimeth
ylsilylmethyl) phthalimide, and (3) photoaddition and photocyclization reac
tions of phthalimide alpha -silyl ether, thioether, amine, and amide system
s.