Photoinduced Electron-Transfer Processes of Phthalimides

To justify the experimental result we could follow the stepwise mechanism discussed in the previous section. The phthalimide system is a good electron acceptor in the excited state and the alkylsilane can be an electron donor, so a photoinduced electron transfer process could lead to the charged separated diradical 13. Transfer of the electrofugal TMS group to the oxyanion carbonyl oxygen would form azo-methyne ylide 14 that can be trapped by the mefliyl acrylate to yield the endo-reaction product 12 (Scheme 16.9). 

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