Visible-light-induced dearomative oxamination of indole derivatives and dearomative amidation of phenol derivatives

Abstract

Herein, we report a protocol for visible-light-induced dearomative oxamination reactions of indole derivatives to afford functionalized spirocyclic products.

Dearomatizing Amination Reactions

“…As demonstrated by Wang and co-workers, irradiation of N-aryl amides 91 by blue LEDs in the presence of Ru(bpy) 3 Cl 2 and acetoxybenziodoxole (BlÀ OAc) results in dearomatization to provide spirocyclic lactams 92 (Scheme 30A). [68] Under the same conditions, but in the presence of a carboxylic acid, indole systems 93 undergo 1,2aminooxygenation to provide products 94 (Scheme 30B). This method is complementary to other recently reported indole…”

Spirocyclizative Remote Arylcarboxylation of Non-Activated Arenes with CO2 via Visible-Light-Induced Reductive Dearomatization

“…[96][97][98] The rationale for this chemoselectivity is not clear at present. Initially, the iodide substrate was also employed, but it was less effective than its bromide analog (55). It should be mentioned that the original carboxylic acid product was isolated in a lower yield than its methyl ester product 55.…”

“…In recent years, visible-light photoredox catalysis [35][36][37][38][39][40][41][42][43][44] has emerged as a promising strategy for developing mild protocols for dearomatization, [45][46][47][48][49][50][51][52][53][54][55][56][57][58] including several significant protocols for the dearomatization of nonactivated arenes, [59][60][61][62][63][64][65][66][67][68][69][70][71][72][73] such as dearomative cycloadditions mainly from the groups of Sarlah and Bach, [59][60][61][62] and oxidative dearomatization. [63][64][65] A distinct redox-neutral hydroalkylative dearomatization of naphthalene derivatives was also reported by the group of Zhang, Mei and You.…”

Spirocyclizative Remote Arylcarboxylation of Nonactivated Arenes with CO 2 via Visible-Light-Induced Reductive Dearomatization

“…We suspected the product might be labile, resulting in a relatively lower yield. Gratifyingly, substrates bearing a series of substituents on the indole ring or the aryl bromide ring could be converted into the corresponding products in moderate yields (56)(57)(58)(59)(60)(61)(62)(63)(64)(65). It should be mentioned that generally about 5% product of arylcarboxylation of indole's C2-C3 double bond, and side products from debromination (about 5%) as well as hydroarylation of the 2-phenyl group (generally less than 5%) were also observed.…”

“…In recent years, visible-light photoredox catalysis [36][37][38][39][40][41][42][43][44][45] has emerged as a promising strategy for developing mild protocols for dearomatization, [46][47][48][49][50][51][52][53][54][55][56][57][58][59] including several significant protocols for the dearomatization of nonactivated arenes, [60][61][62][63][64][65][66][67][68][69][70][71][72][73][74] such as dearomative cycloadditions that were mainly from the groups of Sarlah and Bach, [60][61][62][63] and oxidative dearomatization. [64][65][66] A distinct redox-neutral hydroalkylative dearomatization of naphthalene derivatives was also reported by the group of Zhang, Mei and You.…”