Nitrogen-Containing Functionalities

The organic chemical structural types believed to be characteristic of coals include complex polycyclic aromatic ring systems with connecting bridges and varied oxygen-, sulfur-, and nitrogen-containing functionalities. 

Poly (acetylenes) [16], There are several catalysts available for polymerization of substituted acetylenes. Whereas Ziegler-Natta catalysts are quite effective for polymerization of acetylene itself and simple alkylacetylenes, they are not active towards other substituted acetylenes, e.g. phenylacetylenes. Olefin-metathesis catalysts (Masuda, 1985 Masuda and Higashimura, 1984, 1986) and Rh(i) catalysts (Furlani et al., 1986 Tabata, 1987) are often employed. In our experience, however, many persistent radicals and typical nitrogen-containing functional groups serve as good poisons for these catalysts. Therefore, radical centres have to be introduced after construction of the polymer skeletons. Fortunately, the polymers obtained with these catalysts are often soluble in one or other organic solvent. For example, methyl p-ethynylbenzoate can be polymerized to a brick-coloured amorph- See the Appendix on p. 245 of suffixes to structural formula numbers. 

Isocyanides are converted, on addition of f-BuLi at the electrophilic carbon atom, to lithioimines—another class of anionic, nitrogen-containing functions which turn out to have good orf/zo-directing ability. The electrophile reacts at both lithium-bearing centres of 129 (Scheme 56). 

TTie introduction of nitrogen-containing functions (e.g., NMe) into the crown ether constitution has a profound effect (73) on both the structures and strengths of molecular complexes with organic substrates. 

S. G. Lister, Gen. Synth. Methods 10, 230-319 (1988) Amines, Nitriles, and Other Nitrogen-containing Functional Groups [prepared by General and Synthetic Methods],... 

Table 2.5 Some Important Nitrogen-Containing Functional Groups Present in Anthropogenic Organic Compounds...

Figure 2.18 Examples of industrially and/or environmentally important chemicals exhibiting primarily nitrogen-containing functional groups. Some of the common uses and/or sources of the chemicals are given in parentheses.

Many nitrogen-containing functional groups react with fluorine to give a variety of products Several reagents add fluorine to nitro anions, as shown in equations 7 and 8 r66, 67, 68] A detailed review of these reactions was recently published [69]... 

Chemical Reactions. The reactions of dimer acids were reviewed fully in 1975. 1716 most important is polymerization the greatest quantities of dimer acids are incorporated into the non-nylon polyamides, Other reactions of dimer acids that are applied commercially include polyesterification, hydrogenation, esterification, and conversion of the carbuxy groups to various nitrogen-containing functional groups. 

Oxidation of alcohols with a nitrogen-containing functionality at the 4 position, resulting in aminals with no over-oxidation to lactams.85... 

Amines are saturated, nitrogen-containing functional groups that are widely encountered. Because the nitrogen atom of amines is basic, nucleophilic, and oxidizable, some constraints on the preparation of amines result. A collection of textbook amine preparations includes the following ... 

As these compounds all possess a nitrogen-containing functional feature, it is worth pointing out that they arise from alkyl halides (or methanesulphonates) in the case of azides and cyanides, or from carboxylic acid chlorides (in the case of amides). 

Aside from the various classes of nitrogen containing functional groups with which we are familiar, entire fields of study have developed based on nitrogen-containing compounds. These fields include alkaloids, peptides and/or proteins, and nucleic acids. For purposes of study by NMR, the nucleic acids are a favorite subject because not only is nitrogen ubiquitous in these compounds but so is phosphorus (see Section 6.5). 

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