Iron(iii)-catalyzed chelation assisted remote C–H bond oxygenation of 8-amidoquinolines

Abstract

Iron catalyzed site selective and chelation assisted C-H functionalization in 8-amidoquinolines is achieved. The remote C5-benzoxylation with benzoyl peroxide produced a variety of potentially bioactive 8-arylcarboxamido-5-benzoyloxy quinoline derivatives. The efficiency of the reaction reflects from the wide substrate scope with electronic differentiation on carboxamide and acyl peroxide in addition to tolerance of halo-substitutions on either of the aryls. The reaction is additive, silver free and proceeds without the exclusion of air or moisture.

Thermoinduced Free-Radical C–H Acyloxylation of Tertiary Enaminones: Catalyst-Free Synthesis of Acyloxyl Chromones and Enaminones

“…In light of the free-radical pathway involved in the previous chromone synthesis based on the enaminone C–H coupling and the many known practical methods on radical-based C–H functionalization reactions, we envisage that an O -centered free-radical precursor would thus be applicable to design the expected C–O bond forming reaction. With this inspiration, the frequently utilized aroyl peroxides are thus elected as the radical precursors . Herein, we report the first example on the synthesis of 3-acyloxylated chromones and tertiary enaminones via the free-radical-based C–H cross-coupling of tertiary enaminones by using aroyl peroxide.…”

DABCO-mediated synthesis of aromatic esters from phenols, naphthols or 3-hydroxypyridines and aryl acyl peroxides at room temperature

“…After washing with water (3×5 mL) and methyl tert-butyl ether (3×5 mL), the solid was recrystallized with cold acetone/water mixture (1:3 V/V). 35 General procedure for DABCO-mediated synthesis of aromatic esters. In a dry 10 mL reaction tube were added 2-naphthol (1.0 mmol), benzoyl peroxide (0.2 mmol), triethylenediamine (0.4 mmol), and then 1,2dichloroethane solution (2 mL).…”

Iron-Catalyzed Remote C–H Alkylation of 8-Amidoquinolines with Cycloalkanes

“…Based on the results of the control experiments and literature precedents, [17][18][19] we propose a possible reaction mechanism as shown in Scheme 4. The Fe(II) precatalyst A would be first oxidized by DTBP to an Fe(III) species B with concomitant generation of tert-butoxy radical.…”