24142-83-4Relevant academic research and scientific papers
N -Arylbenzo[ b ]phenothiazines as Reducing Photoredox Catalysts for Nucleophilic Additions of Alcohols to Styrenes: Shift towards Visible Light
Seyfert, Fabienne,Wagenknecht, Hans-Achim
, p. 582 - 586 (2021)
N -Phenylphenothiazines are an important class of photoredox catalysts because they are synthetically well accessible, they allow the tuning of the optoelectronic properties by different substituents, and they have strong reduction properties for activation of alkenes. One of the major disadvantages of N -phenylphenothiazines, however, is the excitation at 365 nm in the UV-A light range. We synthesized three differently dialkylamino-substituted N -phenylbenzo[ b ]phenothiazines as alternative photoredox catalysts and applied them for the nucleo philic addition of alkohols to α-methyl styrene. The additional benzene ring shift the absorbance bathochromically and allows performing the photocatalyses by excitation at 385 nm and 405 nm. This type of photoredox catalysis tolerates other functional groups, as representatively shown for alcohols as substrates with C-C and C-N triple bonds.
Nucleophilic Alkoxylations of Unactivated Alkyl Olefins and α-Methyl Styrene by Photoredox Catalysis
Seyfert, Fabienne,Mitha, Mathis,Wagenknecht, Hans-Achim
supporting information, p. 773 - 776 (2021/01/12)
N,N-diisobutylaminophenyl-phenothiazine is a strongly reducing catalyst that allows – for the first time – the photoredox catalytic addition of alcohols to alkyl olefins as non-activated substrates to products with Markovnikov orientation. The irradiation at 365 nm does not require any additional reagent. Using α-methyl styrene as activated substrate we additionally show that this photoredox catalytic method tolerates other functional groups, including allyl, alkynyl, cyanide, and even acid-labile Boc groups within the substrate scope.
