Photochemistry photoreduction, intramolecular

The photochemistry of phthalimide systems was thoroughly investigated by many groups over the last two decades. This chromophore shows a broad spectrum of reactivity leading mainly to cycloaddition and photoreduction products by either intermolecular or intramolecular processes. In the presence of electron donors, the electronically excited phthalimide could also undergo electron transfer and act as an electron acceptor. 

Recent work on the photochemistry of ketimines has shown that they do not undergo reduction unless ketones are present. Thus chemical sensitization is entirely responsible for the photoreduction of benzophenone methylimine (22)105 while intramolecular chemical sensitization has been suggested as the mechanism for reduction of the acylketimine (23).119 In related work,... 

Intramolecular H-abstraction in CD molecules selectively derivatized with photoactive units was also reported. These systems have potential as starting compounds for producing other substituted CDs. Both an-thraquinone (130-132) and benzophenone (133) derivatives of /3-CD were synthesized by Abelt and co-workers (Scheme 41) [366,367]. The photochemistry was studied in water/2-propanol and water/acetonitrile solutions. Photoreduction of the carbonyl group was attributed to intermolecular... 

The solution photochemistry of a,/8-unsaturated ketones has received a great deal of attention. It is found that the course of the photoreactions is sensitive to small variations in the structure of the reactant, the concentration of the reactant, and the solvent. The reactions observed thus far involve structural rearrangements which may be accompanied by reaction with the solvent, photoreduction, both inter- and intramolecular, and dimerization. 

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