Photocatalyst-, metal- and additive-free regioselective radical cascade sulfonylation/cyclization of benzimidazole derivatives with sulfonyl chlorides induced by visible light

Abstract

Herein, an environmental and practical protocol for the visible-light-triggered regioselective radical cascade sulfonylation/cyclization of unactivated alkenes towards synthesis of polycyclic benzimidazoles containing sulfone group has been developed. Notably, the control...

Alkyl radicals from diacyl peroxides: metal-/base-/additive-free photocatalytic alkylation of N-heteroaromatics

“…Since the renaissance of photoredox catalysis in 2008, 4 a range of synthetically meaningful transformations enabled by light irradiation have been developed. 5 In this context, room-temperature decarboxylative transformations of diacyl peroxides could be realized under the irradiation of visible light. 6 Although the research groups of Li 7 and He 8 independently reported a blue light-induced arylation of quinoxalin-2(1 H )-ones with aryl diacyl peroxides under room temperature without any external photocatalysts and additives, the application of alkyl diacyl peroxides as alkylating reagents under visible-light irradiation at room temperature still a daunting challenge.…”

Photocatalysis as a green alternative toolkit for the construction of nitrogen-enriched heterocycles via the direct and indirect activation of alkynes/alkenes

“…As shown in Table 20C, Jin and co-workers created a sulfonyl chloride photoinitiated C–S coupling aided cyclization of N -allyl benzimidazole molecules ( 717 ). 117 The chlorine radical could act as a proton removal reagent in this process. Using a variety of N -allyl benzimidazoles ( 717 ) and sulfonyl chlorides ( 718 ), about 38 instances of six-membered cyclic benzimidazoles ( 719 ) were synthesized in yields of up to 89% in this investigation.…”

Radical Cascade Cyclization of Alkene‐Tethered Compounds: Versatile Approach towards Ring‐Fused Polycyclic Structures

“…[101] Jin and co-workers reported a visible-light induced radical cascade sulfonylation/ cyclization with sulfonyl chlorides under photocatalyst-, metaland additive-free conditions (Scheme 58c). [102] Wu and co-workers achieved the construction of perfluoroalkylated tricyclimidazoles under copper-catalyzed conditions with perfluoroalkyl Iodide (Scheme 58d). [103]…”