Design and application of aminoacridinium organophotoredox catalysts

Abstract

The design, modular synthesis and applications of aminoacridinium photoredox catalysts (e.g. R1 = NMe2) with a broad range of redox properties and compatibility with complex substrates and reaction mixtures are highlighted in this feature article.

Photocatalysis with organic dyes: facile access to reactive intermediates for synthesis

“…In the last years, several classes of organic dyes, such as acridiniums (OD1-4), cyanoarenes (OD5-8), diaryl ketones (OD9/ 10), flavins (OD11/12), xanthenes (OD13-15), thiazines (OD16/17) and various other dyes, such as OD18-21, have been exploited (Figure 1), and the field of organic photocatalysis has been extensively covered by various reviews [16,[19][20][21][22][23][24][25]. Most of these reports are organized according to the structural features of the dye and/or their applications in synthetic chemistry.…”

Synthesis of Acridinium Photocatalysts via Site-Selective C–H Alkylation

“…Note that electrolysis in the absence of TEMPO resulted in sluggish conversion. This method demonstrated excellent compatibility with primary (3-10), secondary (11)(12)(13)(14)(15)(16)(17)(18), and tertiary (19)(20)(21)(22) alkylorganotrifluoroborates, providing easy access to acridinium dyes with different steric properties. A highly useful feature of our method is that the monoalkylated product can be alkylated again following the above experimental procedures to furnish novel, 3,6-dialkylated acridinium dyes, using the same (28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45) The alkylation reaction could be scaled up to decagram without difficulty by employing a continuous-flow photochemical reactor 45,46 and a electrochemical batch reactor, as demonstrated in the synthesis of 10.88 g of 36 in 80% yield (Fig.…”

Emerging Organic Photoredox Catalysts for Organic Transformations

“…Given the synthetic ease and functional group tolerance, it is expected to easily expand the PC library which would be beneficial for understanding the photophysical characteristics. The recent development in modular synthesis of aminoacridiniums with their applications and catalytic parameters are well summarized by Sparr and co‐workers …”