Visible-light-induced 4CzIPN/LiBr system: a tireless electron shuttle to enable reductive deoxygenation of N-heteroaryl carbonyls

Abstract

Herein, we report a visible-light-induced photoredox system that enables efficiently reductive deoxygenation of N-heteroaryl ketones and methanols under mild conditions. The combinational use of 4CzIPN as photocatalyst and LiBr as...

Stoichiometric couplings of methylarenes through visible-light-induced bromo radical formation from aryl halides

“…Aryl Ni II bromide C underwent visible-light-induced single-electron oxidation to provide an aryl Ni II species D and an active bromine free radical ( E red 1/2 = +0.80 V vs. the SCE in dimethoxyethane (DME)). 20 In addition, the Stern–Volmer quenching experiment for the excited Ir complex with NH 4 Br was conducted and the emission intensity of the PC1 catalyst solution was strongly affected by the gradual increase of the amount of NH 4 Br. This result proved that this SET process could generate an active bromine radical via cleavage of the Ni–Br bond.…”

1,2-Radical Shifts in Photoinduced Synthetic Organic Transformations: A Guide to the Reactivity of Useful Radical Synthons

“…66 In 2021, a deoxygenative reduction of carbonyl compounds under photoredox and metal-free conditions was reported by Huang's group (Scheme 21). 69 In their protocol, heteroaryl ketones undergo PCET, affording the corresponding radical 112. Subsequently, the aromatization driven RS event occurs to generate the hydroxymethyl radical cation intermediate 113, which after protonation followed by the SET step gives the hydroxymethylpyridine intermediate 114.…”

Nickel/Photoredox-Catalyzed Direct Amidation of Aldehydes with Nitroarenes via Fully Catalytic Process

“…In the absence of a base or with the replacement of Na 2 CO 3 with another base, the yield substantially decreased (entries 10–11). When the ratio of aldehyde to nitrobenzene was 1:1, the yield decreased to 46% (entry 12), while three equivalents of aldehydes being exploited meant the aldehydes would serve as a reductant (see Supporting Information for details) . When using n -butyraldehyde, the desired product was obtained in a 21% yield without a photocatalyst, while the corresponding amide was not produced in the absence of Ni/ L1 or light (entries 13–15, see Supporting Information for details).…”