2,4-Dimethyl-5,6,7,8-tetrahydroquinoline

The antiviral agent virantmycin is an unusual chlorinated tetrahydroquinoline isolated from a strain of Streptomyces (Figure 6.10). Hydrolysis of a prochiral 2,2-disubstituted dimethyl malonate with PLE in DMSO-pH 8 phosphate buffer (1 4) was a key step in a stereodivergent synthesis of this natural product [57]. 

A number of related couplings have been reported during the synthesis of the alkaloid ( )-cryptopleurine149 and also intramolecular coupling of diaryl amides to dibenzazepine and dibenzazodne structures.150 A versatile method for the preparation of tetrahydroquinolines and jololidines has been developed.151 The method involves the anodic oxidation of AT,AT-dimethyl-aniline in methanol to afford a-methoxylated or a, a -dimethoxylated compounds and subsequent treatment of products with Lewis acids in the presence of olefins. 

Enamines derived from aldehydes react with SchifFs bases in methanol in the presence of toluene-/ -sulphonic acid to yield tetrahydroquinolines thus l-morpholino-2-methyl-propene and benzylideneaniline afford 3,3-dimethyl-4-morpholino-2-phenyl-l,2,3,4-te-trahydroquinoline 238 (equation 100)123. 

A similar reaction is found in the formation of 5-amino-l-cyano-2,4-dimethyl-3.106-dihydrobenzo[c][2,7]naphthyridine by reduction of 3,5-dicyano-2,6-dimethyl-4-(2-nitro-phenyl)-l,4-dihydropyridine [87] and tetrahydroquino[2,l-c]benzodiazepines from 2-cyano-l-(2-nitrobenzyl)-l,2,3,4-tetrahydroquinoline [88], When the hydroxylamino group has a choice between a nitrile or an ester group, as in 3-ethoxycarbonyl-5-cyano-2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine, it condenses with the nitrile in acidic solution and with the ester in basic media [89]. 

The thermolysis of 2,1-benzothiazoline 2,2-dioxides generates aza-o-xylenes which are trapped in situ with maleic acid derivatives to give cw-l,2,3,4-tetrahydroquinoline-2,3-dicarboxylic acid products (Scheme 11) <91SL571>. 3,3-Dimethyl-2,3-dihydro-1,2-benzisothiazole 1,1-dioxide compounds... 

Anodic oxidation of N, N.-dimethylaniline in methanol yields the -methoxylated derivative (72), which reacts with substituted alkenes in the presence of Lewis acid to give a wide range of tetrahydroquinolines (e.g. 73).94- The adduct (75) from N-methylaniline and allene-1,3-dicarboxylic acid dimethyl ester (7 ) can be converted into the 4-quinolone (76) on treatment with polyphosphoric acid. 95 The use of nitrobenzenes as quinoline precursors is exemplified by the reaction sequence depicted in Scheme 17. The transition-metal-catalysed transformation is thought to involve the reduction of the nitrobenzene to the corresponding aniline via a nitrene intermediate.96... 

Accelerator. A large number of chemical accelerators have been developed which can catalyze the anaerobic cure and reduce the large differences in cure speed on different surfaces. The most commonly used accelerators are saccharin [benzoic sulfimide (II)] and aromatic amines such as A,A-dimethyl-p-toluidine (III) and 1,2,3,4-tetrahydroquinoline (IV). 

The [Ir(ppy)2bpy] complex photo-catalyses inter- and intramolecular C-H functionalisation reactions of tertiary amines under the visible light irradiation. Oxygen behaves as a chemical switch, triggering different reaction pathways and leading to different products from the same starting material. In anaerobic conditions, the intermolecular addition of iV,iV-dimethyl-anilines to electron-deficient alkenes yields y-amino nitriles. Aerobic conditions, on the other hand, favour a radical addition/ cyclisation reaction, leading to tetrahydroquinoline derivatives. The intramolecular version of the radical addition produces unexpectedly indole-3-carboxaldehyde derivatives. ... 

C9H11NO2, Octahydroquinoline-2,5-dione, 42B, 201 C9H11NO2 f 5-Hydroxy-5,6,7,8-tetrahydroquinoline-1-oxide, 41B, 319 C9H13AuClaN203, Hydronium tetrachloroaurate(111) - 2,2-dimethyl-2H-benzimidazole 1,3-dioxide, 43B, 327 C9H13NO3, 7a-Carboxy-7i3-methyl-8-oxo-6aH-1-azabicyclo[4.2.0]octane, 41B, 314... 

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