Heterocyclic compounds indole

J. E. Saxton, ed., The Chemistiy of Heterocyclic Compounds. Indoles. Part Four. The Monoterpenoid Indole Alkaloids. Wiley, New York, 1983. 

The Chemistry of Heterocyclic Compounds, Indoles (Part 1), Houlihan, W. J., ed. Wiley Sons New York, 1972. (Review). 

V-Bromosuccinimide (NBS) supported on silica is a versatile reagent for controlled bromination of a variety of heterocyclic compounds. Indole, carbazole, benzimidazole,... 

From their pyrolysis studies (850°C, N2) with lysine, leucine, and tryptophan, Patterson et al. (2902) reported that each yielded the V-heterocyclic compounds indole, quinoline, isoquinoline, several nitriles, and PAHs ranging from bicyclic to tetracyclic (see Table XXV-16). B[a]P was found... 

A. Weissberger, E. C. Taylor, The Chemistry of Heterocyclic Compounds — Indoles, Wiley-Interscience, New York, 1972. 

There are a number of other sources of information available about the synthesis of indoles. The most comprehensive entree to the older literature is through Volume 25, Parts I-IIl, of The Chemistry of Heterocyclic Compounds, which were published between 1972 and 1979[23]. Work to the early 1980s is reviewed in Comprehensive Heterocyclic Chemistry[24 and a second edition is forthcoming[25]. Other reviews emphasizing recent developments are also availablc[26-28]. 

Intramolecular cyclization in perfluoroaromanc systems proves useful for the synthesis of heterocyclic compounds [72] For example, the Fischer indole synthesis, which normally requires the presence of an ortho proton, occurs satisfactonly with an ortho fluonne in theperfluoronaphthalene senes [73] (equation 37)... 

W. C. Sumpter and F. M. Miller, Heterocyclic Compounds with Indole and Carbazole Systems, p. 50. Wiley (Interscience), New York, 1954. 

Oddo reported that the organomagnesium derivatives of p3Trole, indole, skatole, and carbazole could be prepared in a single operation by mixing the parent heterocyclic compound with an alkyl halide and magnesium in anhydrous ether.The product formed was reported to be the same as that obtained by the more conventional procedure. However, this approach to the synthesis of the indole Grignard reagents does not seem to have been exploited in subsequent work. 

The tenth volume of this serial publication comprises six chapters, four of which deal with the general chemistry of a specific group of heterocyclic compounds pyridopyrimidines (W. J. Irwin and D. G. VVibberley), benzofuroxans (A. J. Boulton and P. B. Ghosh), isoindoles (J. D. White and M. E. Mann), and pyrylium salts (A. T. Balaban, W. Schroth, and G. Fischer). The remaining chapters are concerned with indole Grignard reagents (R. A. Heacock and S. Kasparek) and with cyclic hydroxamic acids (J. B. Bapat, D. St. C. Black, and R. C. Brown).The international flavor of the publication is preserved our contributors come from six countries in three continents. 

As discussed in Chapter 6, nitro compounds are converted into amines, oximes, or carbonyl compounds. They serve as usefid starting materials for the preparation of various heterocyclic compounds. Especially, five-membered nitrogen heterocycles, such as pyrroles, indoles, ind pyrrolidines, are frequently prepared from nitro compounds. Syntheses of heterocyclic compounds using nitro compounds are described partially in Chapters 4, 6 and 9. This chapter focuses on synthesis of hetero-aromadcs fmainly pyrroles ind indolesi ind saturated nitrogen heterocycles such as pyrrolidines ind their derivadves. 

Meerwein reactions can conveniently be used for syntheses of intermediates which can be cyclized to heterocyclic compounds, if an appropriate heteroatom substituent is present in the 2-position of the aniline derivative used for diazotization. For instance, Raucher and Koolpe (1983) described an elegant method for the synthesis of a variety of substituted indoles via the Meerwein arylation of vinyl acetate, vinyl bromide, or 2-acetoxy-l-alkenes with arenediazonium salts derived from 2-nitroani-line (Scheme 10-46). In the Meerwein reaction one obtains a mixture of the usual arylation/HCl-addition product (10.9) and the carbonyl compound 10.10, i. e., the product of hydrolysis of 10.9. For the subsequent reductive cyclization to the indole (10.11) the mixture of 10.9 and 10.10 can be treated with any of a variety of reducing agents, preferably Fe/HOAc. 

The combination of silyl enol ethers and fluoride ion provides more reactive anions to give alkylated nitro compounds in good yields after oxidation with DDQ, as shown in Eq. 9.22.36 This process provides a new method for synthesis of indoles and oxyindoles (see Chapter 10, Synthesis of Heterocyclic Compounds). 

The following are syntheses of indoles and derivatives For an extensive review of indole syntheses and reactions see CHEMISTRY OF HETEROCYCLIC COMPOUNDS (W.J. Houlihan, Ed.), 25, parts 1, 2 and 3 (1972-3). 

Once again, the deoxygenation of nitro-compounds has found use in the synthesis of heterocyclic compounds.62-64 Several 2-nitrophenyl-substituted indoles, e.g. (50) and (51), are deoxygenated on reaction with triethyl phosphite.62 The reaction of... 

Another important example of oxidative cyclization leading to bridgehead heterocyclic compound is the conversion of indole derivative 211... 

Various organolithium intermediates may be posmlated for the synthesis of functionalized indoles and other heterocyclic compounds, from substituted Af-allylanilines (331a-c) or the cychc analog 332, on treatment with f-BuLi. For example, in equation 81 intermediate 333, derived from 331a, was quenched with deuterium oxide. Participation of benzyne metallated intermediates, such as 334, derived from 332, is surmised in equation 82 and other processes. The products of equations 81 and 82 can be characterized by H and NMR spectra . 

Oxime derivatives of heterocyclic compounds, such as pyrrole and quinoline, were proposed as anti-inflammatory agents, probably due to their ability to inhibit the biosynthesis of leukotrienes . Inhibition of 5-lipogenase by oximes of biphenyl sulfides , and by 0-aIkylcarboxylate oximes of indole " , were suggested as key leads for the development of efficient anti-inflammatory drugs. 

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