Formal intramolecular photoredox chemistry of meta-substituted benzophenones.
[reaction: see text]. Photolysis of 3-(hydroxymethyl)benzophenone (1) in aqueous solution (pH < 3) results in clean formation of 3-formylbenzhydrol (2) at dilute (<10(-4) M) conditions. Evidence suggests that the highly efficient (Phi approximately 0.6) reaction involves a unimolecular mechanism and an overall formal intramolecular photoredox process, which requires electronic communication between the 1,3-positions of the benzene ring, an unprecedented example of the photochemical meta effect. The photoredox reaction was not observed in organic solvents, where only photoreduction of the benzophenone moiety was observed.
Mitchell
Devin
D
Department of Chemistry, University of Victoria, British Columbia, Canada.
Lukeman
Matthew
M
Lehnherr
Dan
D
Wan
Peter
P