Unsaturated Nitrogen Compounds

It has been tentatively suggested that one mechanism underlies the Willgerodt reaction and the Kindler modification of it. A labile intermediate is first formed which has a carbon—carbon bond in the side chain. The scheme is indicated below it postulates a series of steps involving the addition of ammonia or amine (R = H or alkyl), elimination of water, re addition and eUmination of ammonia or amine until the unsaturation appears at the end of the chain then an irreversible oxidation between sulphur and the nitrogen compound may occur to produce a thioamide. 

Thus, in spite of its lack of reactivity, iodine reacts chemically with unsaturated compounds, whereby the silica gel of the TLC layer can sometimes be assigned a catalytic role [11, 12]. Irreversible oxidations and electrophilic substitution and addition reactions have been observed on the interaction of iodine with tertiary nitrogen compounds such reactions possibly depend on particular steric relationships or are favored by particular functional groups [13, 14]. 

A close analogy to the carbon radicles is provided by certain nitrogen compounds, which are likewise free unsaturated complexes partaking of the character of atoms and having an abnormal valency. With nitrogen, as with carbon, the existence of radicles also depends on the presence of aromatic rings. Tetraphenylhydrazine corresponds to hexa-phenylethane. 

Heptachlor under Unsaturated Alkyl Halides Heptanes under Alkanes and Cyclic Alkanes Heterocyclic Nitrogen Compounds Heterocyclic Oxygen Compounds Heterocyclic Sulfur Compounds... 

The unsaturated molecule Y may be carbon monoxide, an olefin, a conjugated diene, an acetylene, a carbonyl compound, various unsaturated carbon-nitrogen compounds, or probably any of several other unsaturated materials. The reactive part of the covalent metal compound is usually a metal-hydrogen, metal-carbon, metal-oxygen, metal-halogen, metal-nitrogen, or metal-metal group. This reaction... 

Metal Hydrides and Metal-Carbon Compounds. Numerous examples of reductions and additions of metal hydrides or alkyls to unsaturated carbon-nitrogen compounds are known. I shall mention only two examples pertinent to this discussion. 

Pyrrole is a nitrogen-containing unsaturated five-membered heterocyclic aromatic compound. It shows aromaticity by delocalization of a lone pair of... 

A-Acyliminium ions are versatile intermediates for synthesis of nitrogenous compounds, particularly alkaloids [154]. The conjugate system is very electrophilic such that it can be intercepted by various donors including carbonyl compounds and jt-systems. In comparison with a,p-unsaturated ketones the replacement of the a-carbon with a nitrogen atom accentuates the reactivity of these species. Ingenious applications of the JV-acyliminium ions include service to synthesis of corydaline [155], lycoramine [156], quebrachamine [157], and ajmaline [158], to name a very few. 

Similar electroreductive silylation of a series of unsaturated nitrogen compounds such as trimethylsilyl cyanide, cyanamide or isocyanide, bis(trimethylsilyl)carbodiimide and trimethylsilyl isocyanate provide precursors of bis(trimethylsilyl)methylamine, which is useful for organic synthesis (equations 90 and 91)115. This electrochemical method is a safer and more economical process compared with the chemical process using an alkali metal such as lithium. 

The correlation tables for unsaturated nitrogen compounds are in Appendix 2, Table A2.ll. 

Pork fat contains more unsaturated fatty acids than beef and its linoleic acid content is double that in beef. Heat produced volatiles in red meat fats are listed in Table IV. The presence of pyrazines in the volatiles of beef fat is due to the presence of nitrogenous compounds in the fat amounting to 0.1-0.2%N, (Kjeldhal method). These compounds might be proteins, peptides, amino acids, and amine moities in polar lipids. Such compounds... 

---