Inter- and intramolecular-bridge-mediated electron transfer in aliphatic halides

The anionic surfaces of the 1-chloro- and 4-chlorobicyclo2.2.1]heptan-2-one, 1-chloro- and 4-chlorobicyclo2.2.2]octan-2-one, 1-chloro- and 5-chloroadamantan-2-one, and 2-chlorotricyclo7.3.1.0(2,7)]tridecan-13-one were explored using DFT functionals with full geometry optimization in solution. The reductive cleavage of these compounds is controlled by the rigidity of the polycycle, its capability to form an unstrained radical, and by the relative carbonyl/C-Cl disposition on the bridge. Such control can be exerted by either a concerted-dissociative or a stepwise mechanism with radical anions as intermediates. 5-Chloroadamantan-2-one is the most suitable compound to follow the latter pathway.