Metal‐Free Visible‐Light Photocatalytic Tandem Radical Addition–Cyclization Strategy for the Synthesis of Sulfonyl‐Containing Isoquinolinediones

Abstract

A mild radical cascade reaction for the synthesis of sulfonyl‐containing isoquinolinediones has been developed, in which sulfonyl radicals can be accessed from simple sodium sulfinates under visible light and eosin Y catalysis. This tandem approach features a broad range of substrates and functional group tolerance. With this strategy, trifluoromethylated isoquinolinedione was also obtained.

Synthesis and applications of sodium sulfinates (RSO2Na): a powerful building block for the synthesis of organosulfur compounds

“…Subsequently, Zuo et al reported that the eosin-Y catalyzed N -alkyl- N -methacryloyl benzamides with sodium sulfinates under visible light irradiation afforded isoquinoline-1,3(2 H ,4 H )-diones ( Scheme 213B ). 321 Several substituted N -methacryloylbenzamides at different positions of the benzene ring were smoothly reacted with a series of aryl/alkyl sulfinates to produce a wide range of corresponding products in good yields. Sodium trifluoromethanesulfinate was also used, however, the desired trifluoromethylsulfonylation product was not formed.…”

Oxidative Sulfonylation of Multiple Carbon‐Carbon bonds with Sulfonyl Hydrazides, Sulfinic Acids and their Salts

“…[273] A similar transformation was carried out photochemically in DMFÀ H 2 O at room temperature under an inert atmosphere applying sodium sulfinates as sulfonyl radicals source (eosin Y served as the photocatalyst). [274] AgNO 3 -or CAN-mediated reaction of o-vinylanilides 522 with sodium sulfinates 523 under an inert atmosphere led to benzoxazines 524 (Scheme 225). [275] Electric current was also used as the oxidant for this transformation.…”

“…The reaction proceeds as a cascade of radical transformations including the generation of the sulfonyl radical, its addition to the terminal double bond, and radical cyclization with the aromatic ring [273] . A similar transformation was carried out photochemically in DMF−H 2 O at room temperature under an inert atmosphere applying sodium sulfinates as sulfonyl radicals source (eosin Y served as the photocatalyst) [274] …”

Recent Advances on Metal-Free, Visible-Light- Induced Catalysis for Assembling Nitrogen- and Oxygen-Based Heterocyclic Scaffolds

“…The use of cheap, non-irritating sodium sulfinate opens the way to the possibility to generate sulfonyl radicals by means of visible-light-induced catalysis. Zuo et al disclosed a tandem radical addition/cyclization concept for the synthesis of isoquinolinediones [53]. A mild radical cascade reaction is based on sulfonyl radical generation from the appropriate sodium sulfinate 114 and Eosin Y 11a under blue LED irradiation (Scheme 15a).…”