Palladium-catalyzed synthesis of o-acetylbenzoic acids: a new, efficient general route to 2-hydroxy-3-phenyl-1,4-naphthoquinones and indolo[2,3-b]naphthalene-6,11-diones

A New Approach to the Synthesis of Benzo[b]naphtho[2,3-b]furan-6,11-diones and 2-Benzyl-3-hydroxynaphthalene-1,4-diones

“…[15][16][17][18] Accordingly, a range of methods for the preparation of these powerful scaffolds have been developed, including our previously reported general syntheses from o-acetylphenylacetic acids XI (route a) 26 and from o-acetylbenzoic acids XII (route b). 27 Route a was found to be of limited scope because it only allowed benzocarbazolequinones III to be prepared. These tetracyclic naphthoquinones were alternatively obtained through route b, by a sequence involving the condensation of isochroman-1,4-diones XII with p-nitrobenzaldehydes, followed by rearrangement of the resulting 3-benzylideneisochroman-1,4-diones XIII (X = NO 2 ) to the corresponding naphthoquinones (m = 0) and subsequent generation of the nitrogen ring.…”

An Unprecedented Synthesis of 3,3‐Disubstituted Isochroman‐1,4‐diones Using Nitrones as Oxygen Atom Donors

“…). Similarly, isochroman‐1,3‐diones and isochroman‐1,4‐diones are also known to have enhanced biological properties. For instance, gliquidone ( 1 ), the medication prescribed for diabetes mellitus type 2, and sclerin ( 2 ), a plant growth promoting substance, are both synthesized from isochroman‐1,3‐diones (Fig.…”

Synthesis of 1,2-dihydro-2-oxo-4-quinolinyl phosphates from 2-acyl-benzoic acids

“…The synthesis of starting material 2c has been reported previously. 13 Effects of substitution on the phenyl ring have also been studied (entries 5-12). When 2-acetyl-3-chlorobenzoic acid ( 2d ) 13 and 2-acetyl-3-methylbenzoic acid ( 2e ) 13 were used as the starting material, low yields were obtained for reactions in both toluene and DCE (entries 5-8).…”

“…13 Effects of substitution on the phenyl ring have also been studied (entries 5-12). When 2-acetyl-3-chlorobenzoic acid ( 2d ) 13 and 2-acetyl-3-methylbenzoic acid ( 2e ) 13 were used as the starting material, low yields were obtained for reactions in both toluene and DCE (entries 5-8). The low yields are likely due to the steric hindrance of the 3-chloro or 3-methyl groups during the nucleophilic addition of the enol intermediate to the second equivalence of DPPA.…”