An Efficient Approach to Functionalized Indoles from λ³‐Iodanes via Acyloxylation and Acyl Transfer

Abstract

Versatile role of λ3‐iodanes has been identified between the reaction of hydroquinone and β‐enaminones for the synthesis of 5‐acyloxy‐4‐hydroxy indoles. The reaction is proposed to proceed through an intermolecular C−C bond formation, intramolecular cyclization, acyloxylation and 1,4‐acyl migration. The important features of this work include various acyloxylation from λ3‐iodanes and broad functional group tolerance to deliver 34 examples in moderate to good yields.magnified image

Ligand exchange of aryl iodine dicarboxylates to form reagents with differing solubilities

“…Procedure is in accordance with that reported by Wang et al 34 PhI(OAc)2 (1.0 equiv.) and carboxylic acid (2.2 equiv.)…”

Metal-Free Thiocarbamation of Quinolinones: Direct Access to 3,4-Difunctionalized Quinolines and Quinolinonyl Thiocarbamates at Room Temperature

“…6, 147.9, 135.0, 132.8, 132.2, 131.2, 129.8, 127.0, 123.6, 121.9 Phenyl-λ 3 -iodanediyl Bis(3-methoxybenzoate). 19 The product 3i was obtained as a white solid (1558.5 mg, 77%) after purification through a chromatography column (elution: 2% MeOH in dichloromethane). 1 H NMR (400 MHz, CDCl 3 ) δ 8.23 (d, J = 7.5 Hz, 2H), 7.61 (t, J = 7.4 Hz, 1H), 7.55−7.50 (m, 4H), 7.47−7.46 (m, 2H), 7.26 (t, J = 7.9 Hz, 2H), 7.03 (dd, J = 8.2, 1.8 Hz, 2H), 3.80 (s, 6H) ppm.…”

“…Phenyl-λ 3 -iodanediyl (2E,2′E)-Bis(3-phenyl acrylate). 19 The product 3q was obtained as a white solid (1533.8 mg, 77%) after purification through a chromatography column (elution: 2% MeOH in dichloromethane). 1 H NMR (400 MHz, CDCl 3 ) δ 8.21 (d, J = 7.5 Hz, 2H), 7.63 (t, J = 7.4 Hz, 1H), 7.58−7.52 (m, 4H), 7.47−7.45 (m, 4H), 7.39−7.34 (m, 6H), 6.41 (d, J = 16.0 Hz, 2H) ppm.…”

“…The product 4aa was obtained as a white solid (48.8 mg, 66%) after purification through a chromatography column (elution: 3% MeOH in dichloromethane), mp 36−37 °C. 1 H NMR (400 MHz, CDCl 3 ) δ 8.97 (s, 1H), 8.34−8.30 (m, 2H), 8.17 (d, J = 8.5 Hz, 1H), 7.90 (d, J = 8.3 Hz, 1H), 7.79−7.75 (m, 1H), 7.55 (t, J = 7.6 Hz, 1H), 7.24 (t, J = 8.5 Hz, 2H), 2.99 (s, 6H) ppm; 13 C{ 1 H}NMR (101 MHz, CDCl 3 ) δ166.5 (d, J = 256.5 Hz), 164.2,162.7,156.6,156.3,149.8,133.2 (d,J = 9.6 Hz),130.9,129.6,127.4,124.4 (d,J = 2.8 Hz),123.0,121.7,116.1 (d,J = 22.1 Hz), 116.0, 37.0 ppm; 19 3, 163.9, 156.8, 156.3, 149.6, 138.5, 135.9, 130.8, 129.3, 128.2, 127.9, 127.3, 123.1, 121.8, 116.1, 36.9, 21 3-((Dimethylcarbamoyl)thio)quinolin-4-yl 2-(p-Tolyl)acetate. The product 4ac was obtained as a colorless liquid (45.6 mg, 60%) after purification through a chromatography column (elution: 2% MeOH in dichloromethane).…”

“…ppm;19 F NMR (471 MHz, CDCl 3 ) δ −75.01 ppm. HRMS (ESI) m/z: [M + H] + calcd for C 22 H 22 F 3 NO 2 S 2 : 454.1122; found: 454.1098.…”