Substitution with nitrogen

B. Palladium-catalyzed substitution with nitrogen nucleophiles 4d... 

Tetramethyl- or tetraphenyl- (cyclobutadiene)nickel dihalides undergo reductive ligand substitution with nitrogen donor ligands such as 2,2 -bipyridine or 1,4-diaza-1,3-dienes with the addition of sodium metal237. The 2,2/-bipyridyl ligand is readily displaced and reaction of this complex with a variety of olefins and alkynes leads to cycloaddition reactions with the cyclobutadiene ligand. 

Recently even asymmetric allylic substitution reactions using optically active Pd catalysts have become known. - An example of an intramolecular allylic substitution with nitrogen is seen in equation (22). 

Azatides and azapeptides are a-peptide relatives in which one or more of the a-carbons have been replaced by a trivalent nitrogen atom (Figure 18). While azapeptides (a-peptides in which only a portion of the Ca atoms are substituted with nitrogen) have long been known,168 only recently have all-aza chains,... 

A series of l,2-dithiole-3-thiones substituted with nitrogen-containing heterocyclic groups has been prepared for pharmaceutical studies. Groups include pyrazinyl, pyrimidinyl, pyridazinyl, piperidinyl, morpholinyl, and pyrolidinyl.57-60 The dimer of p-methoxyphenylthionophosphine sulfide (29) has been shown to be a versatile reagent for the sulfuration of /3-ketoesters.61 High yields of l,2-dithiole-3-thiones are obtained. However, the method seems to be most suitable for small scale preparations (0.1 mol).62 Keto-... 

Figure 10.26 A common mechanism by which arenes substituted with nitrogen at various oxidation stales can become mutagens. This scheme is highly simplified—other fates might also await the various arenes shown.

V.2.2 Palladium-Catalyzed Allylic, Propargylic, and Allenic Substitution with Nitrogen, Oxygen, and Other Groups 15-17 Heteroatom Nucleophiles... 

The carbonyl groups were also observed to substitute with nitrogen giving non-classical dinitrogen complexes [13]. For managanese, multiple replacement was uncertain... 

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