Visible-Light-Promoted Phosphorylation/Cyclization of 1-Acryloyl-2-cyanoindoles in Green Solvent

Abstract

A visible-light-induced persulfate-promoted cascade phosphorylation/cyclization reaction to access various phosphorylated pyrrolo[1,2-a]indolediones under mild conditions was developed. Notably, the transformation was carried out with diethyl carbonate/H 2 O as a green medium at room temperature. More impressively, traditional metal catalysts and photocatalysts could be effectively avoided. The reactions are simple to operate, easy to scale up, and have good functional group tolerance.

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

“…Yu's group achieved the synthesis of sulfonated/ thiocyanated [111] and phosphorylated [112] pyrrolo[1,2a]indolediones by reacting of 1-acryloyl-2-cyanoindoles with sulfonyl hydrazides, NH 4 SCN or phosphine oxides under visiblelight-induced and persulfate-promoted conditions (Scheme 67). Mechanistically, the addition of radical 67-A to the C=C bond of alkene followed by intramolecular cyclization provides iminyl radical 67-C.…”

Phototriggered Fluoroalkylation/Cyclization of Unactivated 1-Acryloyl-2-cyanoindoles: Synthesis of RCOCF2-Substituted Pyrrolo[1,2-a]indolediones

“…9 Subsequently, a photocatalyzed persulfate-promoted cascade phosphorylation/ cyclization to access various phosphorylated pyrrolo[1,2a]indolediones was developed by the same group (Scheme 1b). 10 Very recently, our group described a convenient method for accessing diverse difluoroalkylated pyrrolo[1,2-a]indolediones via a visible-light-induced PhI(OAc) 2 -promoted cascade difluoroalkylation/cyclization reaction using FeCl 2 as a catalyst (Scheme 1c). 11 Despite the aforementioned works, some efficient synthetic methodologies of functionalized pyrrolo[1,2-a]indolediones have been reported.…”

“…Yu’s group reported the synthesis of sulfonated/thiocyanated pyrrolo­[1,2- a ]­indolediones via the visible-light-induced cascade cyclization of 1-acryloyl-2-cyanoindoles (Scheme a) . Subsequently, a photocatalyzed persulfate-promoted cascade phosphorylation/cyclization to access various phosphorylated pyrrolo­[1,2- a ]­indolediones was developed by the same group (Scheme b) . Very recently, our group described a convenient method for accessing diverse difluoroalkylated pyrrolo­[1,2- a ]­indolediones via a visible-light-induced PhI­(OAc) 2 -promoted cascade difluoroalkylation/cyclization reaction using FeCl 2 as a catalyst (Scheme c) .…”

Visible-Light-Induced Cascade Cyclization of 1-Acryloyl-2-cyanoindole: Access of Difluoroalkylated Pyrrolo[1,2-a]indolediones

“…In 2022, Yu’s group reported an efficient approach for the synthesis of sulfonated/thiocyanated pyrrolo­[1,2- a ]­indolediones employing the radical cascade cyclization of 1-acryloyl-2-cyanoindoles under visible-light irradiation at room temperature (Scheme a) . Very recently, a visible-light-trigged persulfate-facilitated cascade phosphorylation/cyclization reaction for accessing diversity phosphorylated pyrrolo­[1,2- a ]­indolediones under gentle conditions has been disclosed by the same group (Scheme b) . Despite these achievements, it is still a highly significant endeavor to create ecofriendly and sustainable synthetic pathways for the construction of other functionalized pyrrolo­[1,2- a ]­indolediones, which could further promote the application of pyrrolo­[1,2- a ]­indolediones in new drug discovery and synthesis.…”