A room temperature decarboxylation/C–H functionalization cascade by visible-light photoredox catalysis

Abstract

An elegant approach to quaternary oxindole formation has been developed through a room temperature decarboxylation/radical C-H functionalization by visible-light photoredox catalysis.

Visible‐Light‐Induced Trifluoromethylation of N‐Aryl Acrylamides: A Convenient and Effective Method To Synthesize CF3‐Containing Oxindoles Bearing a Quaternary Carbon Center

“…Very recently, we have reported an excellent visible‐light‐driven protocol for the formation of oxindoles containing a quaternary carbon atom by coupling diverse aliphatic carboxylic acids with N ‐aryl acrylamide derivatives (Scheme ) 9a. b, 10 Trifluoroacetic acid was examined under the optimized reaction conditions. Unfortunately, no expected product was obtained.…”

Olefin difunctionalizations via visible light photocatalysis

“…32 Using the visible light photocatalytic conditions, a decarboxylation/C-H functionalization cascade of N-phenylmethacrylamide has been developed, in which a variety of carbonic acids provide alkyl groups through decarboxylation. 33 Zhu has utilized N-aryl acryl amides and carboxylic acid as substrates, Ir(ppy) 3 as the photocatalyst in DMF, with PhI(OAc) 2 as an oxidant, under the irradiation of 35 W fluorescent light bulb to afford the corresponding products in moderate to good yields. Later, an effective photocatalytic methodology for the synthesis of CF 3 -containing oxindoles bearing a quaternary carbon center was explored by the same group (Scheme 21).…”

Radical Reactions for the Synthesis of 3‐Substituted Chroman‐4‐ones

“…In the past decades, the employment of carboxylic acids as feedstock for organic synthesis has drawn considerable attention . Particularly, decarboxylative cascade cyclization reactions have emerged as a powerful method for organic synthesis . In this context, in 2018 our group developed a silver‐catalyzed decarboxylative cascade radical cyclization of tertiary carboxylic acids 65 and o ‐(allyloxy)arylaldehydes 64 for the synthesis of 3‐alkyl‐substituted chroman‐4‐one derivatives 66 (Scheme ) .…”