674783-97-2Relevant articles and documents
Photocatalytic electron-transfer oxidation of triphenylphosphine and benzylamine with molecular oxygen via formation of radical cations and superoxide ion
Ohkubo, Kei,Nanjo, Takashi,Fukuzumi, Shunichi
, p. 1489 - 1500 (2006)
Photooxygenation of triphenylphosphine (Ph3P) to triphenylphosphine oxide (Ph3P=O) with molecular oxygen (O 2) occurs under photoirradiation of 9-mesityl-10-methylacridinium perchlorate ([Acr+-Mes]ClO4-) which acts as an efficient electron-transfer photocatalyst. Photooxidation of benzylamine (PhCH2NH2) with O2 also occurs efficiently under photoirradiation of Acr+-Mes to yield PhCH2N=CHPh and hydrogen peroxide (H2O2). Each photocatalytic reaction is initiated by intramolecular photoinduced electron transfer from the Mes moiety to the singlet excited state of the Acr+ moiety to produce the electron-transfer state (Acr?-Mes?+). The Mes?+ moiety oxidizes Ph3P and PhCH 2NH2 to produce the radical cations (Ph3P ?+ and PhCH2NH2?+, respectively), whereas the Acr? moiety reduces O2 to O2?+. The produced Ph3P?+ binds with O2?+ as well as O2, leading to the oxygenated product (Ph3P=O). On the other hand, proton transfer from PhCH2NH2?+ to O2 ?+ occurs, followed by hydrogen transfer, leading to the dehydrogenated dimer product, PhCH2N=CHPh. In each case, the radical intermediates were detected by laser flash photolysis and ESR measurements to clarify the photocatalytic mechanism.
Synthesis of dibenzocycloketones by acyl radical cyclization from aromatic carboxylic acids using methylene blue as a photocatalyst
Jiang, Hongshuo,Mao, Guijie,Wu, Hongfeng,An, Qi,Zuo, Minghui,Guo, Weihao,Xu, Chunzhao,Sun, Zhizhong,Chu, Wenyi
supporting information, p. 5368 - 5373 (2019/10/11)
An efficient intramolecular radical cyclization reaction via photoredox catalysis was developed for the synthesis of dibenzocycloketone derivatives using methylene blue as a photosensitizer. This strategy could be widely used to synthesize large heterocycles due to the unique reactivity of phosphoranyl radicals formed by a polar/SET crossover between an aromatic carboxylic acid and a phosphine radical cation. Attractive features of this process include generation of an acyl radical by an inexpensive and metal-free photocatalyst, which effectively undergoes a cyclization process.
Synthesis of highly substituted tetrahydrofurans by catalytic polar-radical-crossover cycloadditions of alkenes and alkenols
Grandjean, Jean-Marc M.,Nicewicz, David A.
supporting information, p. 3967 - 3971 (2013/05/09)
Light up my ring: The title reaction is catalyzed by an acridinium/phenylmalononitrile photoredox system. A variety of readily available olefins and unsaturated alcohols can be employed to furnish tetrahydrofuran adducts with complete regiocontrol and up to four contiguous stereogenic centers.