Saturated five-membered nitrogen heterocycles synthesis

Synthesis of Saturated Five-Membered Nitrogen Heterocycles... 

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. 

In a study of synthetic routes to the phorbol class of compounds, Lautens cyclised the stannane 307 (with 5 equiv MeLi, to avoid stannane reincorporation) to the 7,5-fused ring system 3 0 8.138 This reaction also works in the synthesis of analogous saturated five-membered nitrogen and sulfur heterocycles (see below). 

This chapter is one of the first attempts of systematic review of the synthetic methods and chemistry of nonaromatic saturated and unsaturated perfluorinated heterocycles. It summarizes data on the synthesis and chemical transformation of perfluorinated six- and to some extent five- membered nonaromatic heterocyclic compounds containing oxygen, nitrogen, sulfur, selenium, and phosphorous. It should be pointed out that the review is not all-inclusive one, but it is an attempt to provide representative examples of synthetic methods and chemistry of perfluorinated nonaromatic hetero-cychc materials. 

Condensed heterocyclo[n,m-n, b, or cjquinazolines. 52, I Condensed 4-thiazolidinones, 49, I Condensed thiophene systems, tetra- and pentacyclic, 32, 127 Condensed 1,2,4-triazines I. Fused to heterocycles with three-, four-, and five-membered rings, 59, 39 Condensed l,2,4-triazolo[3,4-z) heterocycles, synthesis, 49, 277 Conformational equilibria in nitrogen-containing saturated six-membered rings, 36, I... 

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