Photoinduced Electron-Transfer-Promoted Redox Fragmentation of N-Alkoxyphthalimides

Abstract

A new photoinduced electron-transfer-promoted redox fragmentation of N-alkoxyphthalimides has been developed. Mechanistic experiments have established that this reaction proceeds through a unique concerted intramolecular fragmentation process. This distinctive mechanism imparts many synthetic advantages, which are highlighted in the redox fragmentation of various heterocyclic substrates.

Visible Light Photoredox Catalysis with Transition Metal Complexes: Applications in Organic Synthesis

“…68 Hünig's base is employed as a reductive quencher for *Ru(bpy) 3 2+ , generating the Ru(bpy) 3 + species that transfers an electron to N -alkoxyphthalimide 82 (Scheme 21). The resulting radical anion 83 may undergo a fragmentation to cleave the labile N–O bond and give the benzaldehyde product and the phthalimide radical anion 84 .…”

Generation of Alkoxyl Radicals by Photoredox Catalysis Enables Selective C(sp3)−H Functionalization under Mild Reaction Conditions

“…[2,10] Forexample,heating conditions with azodiisobutyronitrile/tributyltin hydride is required for N-alkoxyphthalimides to generate alkoxyl radicals, [8] and compromises its synthetic scope and functional-group compatibilities (Scheme 1a). [11,12] Theu tilization of unactivated C(sp 3 )ÀHb onds to engage in new CÀCb ond formation is desirable,b ut it is difficult to control the regioselectivity and chemoselectivity. [11,12] Theu tilization of unactivated C(sp 3 )ÀHb onds to engage in new CÀCb ond formation is desirable,b ut it is difficult to control the regioselectivity and chemoselectivity.…”

Visible‐Light Photocatalytic Reduction of Sulfonium Salts as a Source of Aryl Radicals

“…[8] A particularly attractive approach is the design of new catalytic systems. [10] For instance, various radical transformations involving photoreduction of unsaturated/ cyclopropyl ketones, [11] halides, [12] N-alkoxyphthal-A C H T U N G T R E N N U N G imides, [13] keto epoxides/aziridines, [14] azides [15] and diazoniums, [16] based on reductive quenching of transition metal polypyridine complexes or organic dyes have been developed. [10] For instance, various radical transformations involving photoreduction of unsaturated/ cyclopropyl ketones, [11] halides, [12] N-alkoxyphthal-A C H T U N G T R E N N U N G imides, [13] keto epoxides/aziridines, [14] azides [15] and diazoniums, [16] based on reductive quenching of transition metal polypyridine complexes or organic dyes have been developed.…”