Acridinium Salts and Cyanoarenes as Powerful Photocatalysts: Opportunities in Organic Synthesis

Abstract

The use of organic photocatalysts has revolutionized the field of photoredox catalysis, as it allows access to reactivities that were traditionally restricted to transition‐metal photocatalysts. This Minireview reports recent developments in the use of acridinium ions and cyanoarene derivatives in organic synthesis. The activation of inert chemical bonds as well as the late‐stage functionalization of biorelevant molecules are discussed, with a special focus on their mechanistic aspects.

Intercepting Hydrogen Evolution with Hydrogen-Atom Transfer: Electron-Initiated Hydrofunctionalization of Alkenes

“…Carbazolesubstituted dicyanobenzene afforded desired products (23,(34)(35)(36) in excellent yield, which provides a new way to functionalize this class of photoactive molecules. 32 Importantly, cyanopyridines can also participate in the hydroarylation with different types of alkenes (24,26,38). 33 Various substituted styrenes (25)(26)(27)(28)(29)(34)(35)(36) and heteroaromatic alkenes (30)(31)(32)(33) proved to be viable substrates.…”

A batch photoreactor for small-scale laboratory research - a technical note

“…The utilization of photons as green, sustainable and cost-free reagents to drive chemical transformations with the visible-light-excited photoredox catalysts has experienced a great deal of progress over the last decades [1][2][3][4][5] . Consequently, a dizzying array of photochemical test benches have been introduced by different research groups, yet no clear standardization is disclosed.…”

Synthesis of Helical and Planar Extended‐Phenanthridinium Salts

“…Tremendous advances in the field of nitrogen‐based heterocyclic chemistry achieved over the last decades led to a broad range of applications for pharmaceuticals, agrochemicals, dyes, functional materials, and many more [1–3] . Acridinium salts are particularly useful scaffolds and have emerged as an efficient and sustainable class of cationic organic photocatalysts [4–6] . In recent studies, we investigated a short two‐step route towards diverse acridinium salts involving the aryne‐imine‐aryne coupling reaction [7] followed by the subsequent oxidation of the acridane intermediate ( Scheme 1 ,a ) [8,9] …”

“…[1 -3] Acridinium salts are particularly useful scaffolds and have emerged as an efficient and sustainable class of cationic organic photocatalysts. [4][5][6] In recent studies, we investigated a short two-step route towards diverse acridinium salts involving the aryne-imine-aryne coupling reaction [7] followed by the subsequent oxidation of the acridane intermediate (Scheme 1,a). [8,9] Herein, we now disclose the utilization of this methodology for larger polycyclic aryne substrates.…”