Isatins 5.6.11.12- tetrahydro

The reaction of the isatins 9 with cyclohexanones 132 leads to the formation of derivatives of l,2,3,4-tetrahydro-9-acridinecarboxylic acid 133. If R = H the yields of the products 133 amount to 75-100% [19, 20, 65, 118, 123-125], However, it was noticed in [19] that cyclohexanone does not react with a-naphthisatin 10 under the conditions of the Pfitzinger reaction. 

Tetrahydro-j3-carboline reacts with ethyl glyoxylate in acetonitrile generating azomethine ylide ( ,Z)-86. Even the extremely inert a hydrogen of pyrrolidine can be activated in the condensation with isatin leading to ylide ( ,Z)-87 (86CC602). It is surprising that pyridine-2-carbaldehyde also serves... 

Pyrazolo[3,4-Z)]pyridines, the 7-chloro-6-fluoro-2,4-dimethylquinoline and its mercapto-thiadiazolyl or oxadiazolyl quinolines 21 were prepared via Diels-Alder reaction conversion of methyl 2-(3-oxo-3-phenylpropenylamino)benzoate into 3-benzoyl-l.S -quinolin-4-one 22 . A mixture of aniline derivatives and malonic ester gave a variety of 3-aryl-4-hydroxyquinolin-2(l//)-ones 23. Condensation of isatins with ketones afforded quinoline-4-carboxylic acids. 2-Aryl-l,2,3,4-tetrahydro-4-quinolinones 22 and carbazolylquinolone were also prepared. The substitution of 2-chloroquinoline gave the 2-substituted quinolines. Basic alumina has catalyzed the C-C bond formation between 2-hydroxy-1,4-naphthoquinone and 2-chloroquinoline derivative to give 21. Reaction of organic halides with 8-hydroxyquinolines gave the respective ethers. The azodye derivatives of 21 were prepared in the absence of solvent. Silica gel catalyzed the formation of 2-ketomethylquinolines from reaction of 2-methylquinolines with acyl chlorides. 

Mo(CO)3(isatH)(PPh3)] Mo(CO)6 (0.20 g 0.76 mmol), isatin (0.06 g 0.33 mmol), and PPh3 (0.09 g 0.33 mmol) were mixed in ca 30 ml tetrahydro-furan. The mixture was degassed and heated to reflux for 4 hours, where the color of the solution changed from yellow to dark red. The reaction mixture was cooled and the solvent was removed under vacuum. The obtained solid was washed several times with hot benzene and petroleum ether to give brown crystals with a yield of 55% based on the metal. 

Indole-fused pyran-4-ones are prepared in one-pot two-step synthesis. In the first there is the acylation of 1-substituted 3-acetyl-lH-indol-2-ols with acid chlorides using triethylamine as base, in dichloromethane at room temperature. The second consists in the 4ff-pyran-4-one ring formation firom the in situ-obtained 3-acetyl-2-acyloxy-lF/-indole derivatives (13S1235).A highly diastereo- and enantioselective organocatalytic formal hDA reaction of enones with isatins occurs in the presence of amine 34, acid 35, and thiourea 36 to produce spirooxindole tetrahydro-4ff-pyran-4-ones (Scheme 59) (13CEJ6213). 

The Brpnsted acid-mediated formal 3 + 3-cycloaddition reaction of /i-enaminones with cf, -unsaturated aldehydes formed tetrahydroquinolinones. The Yb(NTf2)3-catalysed 3 + 3-cycloaddition reaction of isatin ketonitrones (122) and cyclopropanes (123) yielded spiro[tetrahydro-l,2-oxazine]oxindoles (124) in moderate to good yields and good regioselectivities (Scheme 38). The Cu-catalysed 3 + 3-cycloaddition reaction of propargyl esters with cyclic enamines yielded chiral e r/o-adducts with bicyclo[ .3.1] frameworks. The catalyst was prepared by the combination of Cu(0Ac)2 H20 with a chiral tridentate ferrocenyl-PA(,(V-ligand. The cationic... 

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