Photomediated core modification of organic photoredox catalysts in radical addition: mechanism and applications.

ABSTRACT: Dihydrophenazines and their analogues have been widely used as strong reducing photoredox catalysts in radical chemistry, such as organocatalyzed atom transfer radical polymerization (O-ATRP). However, when dihydrophenazines were employed as organic photoredox catalysts (OPCs) to mediate O-ATRP, the initiator efficiency was nonquantitative due to cross-coupling between dihydrophenazines and radical species. Here, a new kind of core modification for dihydrophenazines, phenoxazines and phenothiazines was developed through this cross-coupling process. Mechanistic studies suggested that the radical species would be more likely to couple with OPC' radical cations rather than the ground-state OPC. Core modification of OPCs could stabilize the radical ions in an oxidative quenching catalytic cycl

SUBMITTER: Zhang Y 

PROVIDER: S-EPMC8279010 | biostudies-literature | 2021 Jul

REPOSITORIES: biostudies-literature