Search

The aza-vinylogous Povarov reaction between α-ketoimines and α,β-unsaturated dimethylhydrazones in the presence of indium trichloride affords 2-acyl-4-alkyl-4-dimethylhydrazonomethyl-1,2,3,4-tetrahydroquinolines with good cis/trans diastereoselectivities. These compounds were readily transformed into highly substituted 2-acylquinolines using a two-reaction sequence involving the oxidative generation of a C-4 nitrile group, followed by its elimination under thermal conditions. Alternatively, a one-pot protocol based on the reaction of hydrazones with magnesium monoperoxyphthalate hexahydrate in refluxing methanol afforded the target 2-acylquinolines in good to excellent yields. This methodology was also extended to the preparation of 2-arylquinolines.

The water-soluble iron(III)[TF5PS4P=meso-tetrakis(pentafluorophenyl)-β-tetrasulfonatoporphyrin] catalyses the selective oxidation, by magnesium monoperoxyphthalate (or H2O2), of 1,2-dimethoxyarenes bearing an electron-withdrawing substituent (CN, CHO, COR) to muconic dimethyl esters which are formed in 30–40% yield and are the only reaction products obtained after CH2Cl2 extraction.

Treatment of N-alkyl-N-allenylmethylanilines with magnesium monoperoxyphthalate in methanol-water underwent tandem transformations to furnish N-alkyl-2-ethenylindoles in good yield.

Electron-rich methoxyarenes were oxidized with high yields (55–100%) and under mild conditions to the corresponding paraquinones by magnesium monoperoxyphthalate in the presence of catalytic amounts of a water-soluble iron porphyrin; the reaction was used to prepare methoxatin.

Mn-porphyrins catalyse the epoxidation of various alkenes by magnesium monoperoxyphthalate: with 0.125–1% of tetra-2,6-dichlorophenylporphinatomaganese(III) acetate as a catalyst, alkene conversion is nearly complete within 0.5–5 minutes at 0 °C and good epoxide yields (60–93%) are obtained.