Quinolines, synthesis from oximes

The quinoline formation from 2,4-dinitrophenyl oximes suggested to us the possibility of generating radical intermediates and prompted us to study the synthesis of cyclic imines by iminyl radical addition to an internal olefinic moiety as shown in Scheme 44. 

The [Ru(bpy)3] photocatalyst was also applied in the following novel visible-light driven processes (i) synthesis of indazolo[2,3-a]quinoline derivatives from 2-(2-nitrophenyl)-l,2,3,4-tetra-hydroquinolines (ii) azido- and amino-trifluoromethylation of alkenes (iii) reduction of nitro compounds to oximes (iv) generation of aryl radicals by visible-light photocatalytic reduction of sulfonium salts. ... 

Very recently, Yu and co-workers reported a one-pot synthesis of phenan-thridines and quinolines (63) from commercially available or easily prepared aldehydes (61) (Scheme 7.42) [112]. The acyl oximes were obtained in sim from aldehydes and hydroxylamine in the presence of p-Cl-benzenesulfonic acid (CBSA) as an additive. Then acyl oximes were subjected to visible-hght photoredox catalyzed cycUzation via an iminyl radical to furnish azaarene products in moderate to good yields. 

Quinolin-2-one, 3-cyano-4-hydroxy-synthesis, 2, 428 Quinolin-2-one, 3,4-dialkyl-Knorr synthesis, 2, 425 Quinolin-2-one, dihydro-Camps synthesis, 2, 418 synthesis, 2, 402 from benzazepinones, 2, 506 from indanone oxime, 2, 487 from indanones, 2, 488 by intramolecular Friedel-Crafts reactions, 2, 421... 

Domino [3+2] cycloaddition/annulation reactions of aminophenyl-ynones 23 with nitrile oxides, generated in situ from chloro oximes 22, allowed the synthesis of isoxazolo[4,5-c]quinolines 24, in satisfactory yields <03EJO1423>. Bromine substituents on naphthoquinones activate and orient 1,3-DC with nitrile oxides. Compound 25 reacted with halo oximes 22 to give regioselectively only unsymmetrical naphthoquinones 26, as polyketide building blocks <03TL8901>. 

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