Metal-free visible-light-driven cascade cyclization reaction to synthesize 2-oxindoles via benzoyl and phenylsulfinyl radicals with acrylamide derivatives

Abstract

A metal-free visible-light-driven cascade cyclization reaction to synthesize 3-methyl-3-acetophenone-2-oxindoles and 3-methyl-3-(methylsulfonyl)benzene-2-oxindoles in yields up to 96% and 99%, via benzoyl and phenylsulfinyl radicals with acrylamide derivatives is reported, respectively. Extensive...

Visible-Light-Mediated Generation of Acyl Radicals from Triazine Esters

“…4,indolin-2one (4h). 15 Flash column chromatography was conducted on silica gel (eluent: EtOAc/petroleum ether = 1:9) to afford 4h. Colorless oil (27.6 mg, 91%).…”

Unified Approach to Diverse Heterocyclic Synthesis: Organo-Photocatalyzed Carboacylation of Alkenes and Alkynes from Feedstock Aldehydes and Alcohols

“…Organic solutions were concentrated under reduced pressure on a Heidolph rotary evaporator. The products obtained were characterized using 1 H NMR, 13 C NMR, and EI-MS. NMR spectra were recorded at 500 and 400 MHz for 1 H and 126 and 101 MHz for 13 C. The chemical shift (δ) for 1 H and 13 C is given in ppm relative to internal standard/residual signals of the solvents (for 1 H NMR (CHCl 3 @7.26 ppm) and for 13 C NMR (CHCl 3 @77.16 ppm) and tetramethylsilane@0 ppm).…”

“…1,138.7,136.5,132.1,131.9,131.7,128.6,127.7,126.5,125.8,125.7,125.4,124.5,123.3,119.9,115.8,52.0,46.6,30.2,5]imidazo[2,1-a]isoquinolin-6(5H)-one (3ag). 6c Yield 84% (31.3 mg); white solid, hexane/EtOAc = 93/7; 1 H NMR (500 MHz, CDCl 3 ) δ 8.53 (d,J = 7.4 Hz,1H),8.34 (d,J = 7.6 Hz,1H),7.84 (d,J = 7.6 Hz,1H),7.75 (d,J = 3.4 Hz,1H),7.59 (d,J = 4.8 Hz,1H),5H),7.11 (t,J = 4.3 Hz,1H),4.26 (d,J = 17.9 Hz,1H), 4.04 (d,J = 17.8 Hz,1H), 1.72 (s, 3H); 13 C{ 1 H} NMR (126 MHz, CDCl 3 ) 13 C NMR (126 MHz, CDCl 3 ) δ 189. 1,173.2,150.1,144.2,142.8,141.7,134.4,132.4,131.8,128.3,...…”

“…6c Yield 95% (35.6 mg); white solid, hexane/EtOAc = 95/5; 1 H NMR (500 MHz, CDCl 3 ) δ 8.55 −8.49 (m, 1H), 8.13 (s, 1H) 142.7,141.8,135.9,134.8,134.7,133.7,131.4,130.1,128.7,128.6,128.2,127.6,126.3,124.5,123.4,120.1,116.0,49.4,46.2,30.4,5]imidazo[2, 1-a]isoquinolin-6(5H)-one (3ac). 6a Yield 78% (31.3 mg); yellow solid, hexane/EtOAc = 93/7; 1 H NMR (500 MHz, CDCl 3 ) δ 8.49 (d,J = 8.4 Hz,1H),8.31 (d,J = 7.6 Hz,1H), 7.86 (t, J = 6.9 Hz, 3H), 7.57 (t, J = 7.4 Hz, 1H), 7.48−7.41 (m, 5H), 7.30 (s, 1H), 4.34 (d,J = 18.3 Hz,1H), 4.06 (d,J = 18.4 Hz,1H), 1.72 (s, 3H); 13 C{ 1 H} NMR (126 MHz, CDCl 3 ) 13 C NMR (126 MHz, CDCl 3 ) δ 196. 0,172.7,149.3,149.1,144.2,143.9,137.9,135.7,133.9,131.8,128.9,128.3,127.9,125.9,125.7,124.9,121.9,…”

“…The generation of acyl radicals at room temperature under mild conditions has been made possible by utilizing photoredox strategies . The existing acyl radical precursors for visible-light-induced carboacylation include anhydrides, ketoacids, , carboxylic acids, aldehydes, acyl chlorides, 4-acyl-1,4-dihydropyridines, etc. (Figure A) .…”