Visible‐Light‐Induced Oxidative Carboazidation of Arylacrylamides

Abstract

A visible‐light‐induced oxidative carboazidation of arylacrylamides by cascade C−N and C−C bond‐forming strategy is reported. Various functional groups are tolerated to afford the desired azide oxindoles in 22–86% yields under the standard conditions. Mechanistic studies demonstrate that the reaction proceeded via a radical pathway.

Palladium-Catalyzed Carbothiolation by Using Thioesters with Formation of a Quaternary Carbon

“…Chemical shifts are reported in ppm with the residual solvent resonance as internal standard (CDCl 3 1 H, = 7.26 ppm, 13…”

“…(d, J = 12.9 Hz, 1H), 3.35 (d, J = 12.9 Hz, 1H), 3.19 (s, 3H), 1.42 (s, 3H); 13 6-Chloro-4-methyl-4-phenylthiomethylchromane (2b) 3 Compound 2b was prepared according to procedure A. Purification by preparative TLC (hexane/dichloromethane = 1/1) afforded 2b as a colorless oil in 79% yield. R f = 0.50 (hexane/ dichloromethane = 1/1).…”

“…1 H NMR, 13 C NMR, and 19 F NMR spectra were recorded on a JEOL AL-400 spectrometer, JEOL JNM-ECX500 spectrometer and a JEOL JNM-ECZR500 spectrometer.…”

“…3,4 When this reaction is performed in the presence of carbon monoxide, an acyl Pd complex is formed from the alkyl Pd complex, which subsequently reacts with various TIPS thioethers TIPS-SR (R = aryl, alkyl) to afford the corresponding thiol esters in high yields. 5 Several variants of this reaction using bis(pinacolato)diboron, 6,7 hexamethyldisilane, 8,9 hexamethyldistannane, 10 diethyl hydrogen phosphonate, 11 tetrabutylammonium acetate, 12 or trimethylsilyl azide, 13 have been reported. [14][15][16][17][18][19][20] Scheme 1 Pd-Catalyzed carbothiolation using TIPS thioethers TIPS-SR. Ipr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene.…”