Porphyrin‐Catalyzed Photochemical C–H Arylation of Heteroarenes

Abstract

Organic dyes are a promising class of photoredox catalysts and offer a meaningful alternative to broadly applied Ru and Ir complexes. We found that porphyrins with tuned physicochemical properties, by tailoring various substituents at the periphery of the macrocycle, are effective in catalyzing the

Visible Light‐Induced C−H Bond Functionalization: A Critical Review

“…Organic dyes are a promising class of photoredox catalysts and offer a meaningful alternative to broadly applied Ru and Ir complexes. Recently, Gryko and co‐workers found that porphyrins, with physicochemical properties tuned by tailoring various substituents at the periphery of the macrocycle, are effective in catalyzing the light‐induced direct arylation of heteroarenes and coumarins with diazonium salts. Under the optimal reaction conditions, the reactions gave moderate to good yields for the arylation of heteroarenes with diazonium salts and different functional groups were well tolerated (Scheme ).…”

Visible‐Light‐Promoted Arylation Reactions Photocatalyzed by Bismuth(III) Oxide

“…The copper‐catalyzed version of this transformation (the Meerwein arylation) has been known since the 1930s, but it suffers from some important drawbacks, such as the usually low yields and the high catalyst loading required . Since then, many variations of the original procedure have been reported (Scheme ), involving both thermal and photochemical reaction conditions . König and co‐workers proved that this transformation can be photocatalyzed by eosin Y,[22a] and that under visible light irradiation the phenyl radical is formed from diazonium salt 1 .…”

Mechanochemical borylation of aryldiazonium salts; merging light and ball milling

“…Additionally, in contrast to solution-based methods, reactions by milling do not suffer from solubility restrictions due to the possibility to bring reactants and catalysts of very different solubility, into close proximity for achieving chemical reactivity. This last aspect is foreseen as highly valuable in transformations using low-soluble PCs (e.g., porphyrins) [ 16 ] or during the photochemical synthesis or modification of polymers [ 17 ].…”