863030-40-4Relevant academic research and scientific papers
Substituent effects in the intramolecular photoredox reactions of benzophenones in aqueous solution
Basaric, Nikola,Mitchell, Devin,Wan, Peter
, p. 561 - 571 (2008/02/12)
A number of α-hydroxy-3-benzylbenzophenones 7-11 have been synthesized for the purpose of studying the effect of a phenyl substituent on the intramolecular photoredox reaction of 3-(hydroxymethyl)benzophenone (5) discovered in our laboratory. This latter compound was found to undergo a unimolecular (formal) intramolecular redox reaction upon photolysis in aqueous acid that results in clean reduction of the benzophenone ketone (to secondary alcohol) and oxidation of the alcohol to aldehyde. Three of the phenyl-substituted compounds with simple phenyl (7), p-methylphenyl (8), and p-methoxyphenyl (9) were found to undergo the acid-catalyzed intramolecular photoredox reaction with the observation that 9 also undergoes a residual photoredox reaction that is not acid-mediated and may in-volve initial photoinduced electron transfer, which is supported by LFP data. The m-methoxyphenyl (10) compound did not undergo the reaction. The trend in observed relative reactivity may be partially rationalized by examining changes in molecular orbital coefficients observed in the calculated HOMOs and LUMOs. The photoredox reaction has also been applied twice in succession in a single compound 11, demonstrating that the photoredox reaction may be useful for sequential photoredox reactions in a multifunctional compound.
Formal intramolecular photoredox chemistry of meta-substituted benzophenones
Mitchell, Devin,Lukeman, Matthew,Lehnherr, Dan,Wan, Peter
, p. 3387 - 3389 (2007/10/03)
(Chemical Equation Presented) Photolysis of 3-(hydroxymethyl)benzophenone (1) in aqueous solution (pH -4 M) conditions. Evidence suggests that the highly efficient (Φ ～ 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.
