Amines acetylenic

Following the action of extraordinary stimulants (hypoxic hypoxia, hypoxia + hyperoxia, hypodynamia + hyperthermia), animals demonstrate an accumulation of malonic dialdehyde with a simultaneous fall of antiradical activity of the liver tissue. A preliminary introduction to rats of acetylene amine 3,4,5-tris(morpho-linopropynyl)-l-methylpyrazole 103 and also of tocopherol antioxidant and gutumine antihypoxant averts activation of the lipid peroxidation processes. The inhibition of peroxidation with this agent is mediated by stabilization of ly-zosomal and mitochondrial membranes. Unsaturated amines prevent destruction of the organelle membranes provoked by UV irradiation and incubation at 37°C (pH4.7)(78MIl). 

A synthetic method for the preparation of chiral a- and p-allenic alcohols starting with a chiral acetylenic amine 20 and involving an LAH reduction as a key step was reported by Claesson and Mosher (54). This is illustrated in Scheme 3. Based on the stereochemistry of 20 to 24, it can be deduced that the attack... 

The ability of allylzinc bromide to add to terminal alkynes was first observed with acetylenic amines as substrates. Thus, the propargylic amine 290 underwent addition of allylzinc bromide in refluxing THF and afforded after hydrolysis the allylic amine 291. This reaction occurred much more easily compared to the case of ethylenic amines (see Section III.A) and the regioselectivity was also noteworthy as a branched product was obtained predominantly82,105. It was suggested that metallation of the terminal alkyne was responsible for the observed regioselectivity. Indeed, the formation of an alkenyl... 

In addition to the commercially available 2,2,6,6-tetramethylpiperidine, di-tert-alkylamines have been prepared by Rathke7 by the copper-catalyzed coupling of acetylenic amines with acetylenic chlorides in an improvement of the procedure of Hennion.8 Di-tert-butylamine has been synthesized by the reaction of 2-methyl-2-nitropropane with sodium, followed by reduction. ... 

Treatment of cyclohexa-l,3-dione with this acetylenic amine gives a stable enamine in good yield. Refluxing this enamine in nitrobenzene gives a pyridine after a remarkable series of reactions. Fill in the details give mechanisms for the reactions, structures for any intermediates, and suitable explanations for each pericyclic step. A mechanism is not required for the last step (nitrobenzene acts as an oxidant). 

The Sonogashira coupling can be considered a special case of catalytic alkyne activation. Interestingly, it is also possible to conduct alkyne activation under oxidative conditions in the presence of Pd catalysts without oxidative dimerization. Here, Costa and coworkers [139] have developed a Pd-catalyzed sequential carboxylation-alkoxycarbonylation of acetylenic amines in the presence of oxygen to give mixtures of Z- and -configurcd 2-oxo-oxazolidin-5-ylidene]-acetic acid methyl ester 193 and 194 in good to excellent yields (Scheme 75). 

Acetylene-Amine additions Cadmium acetate-Zinc acetate. 

FIGURE 15.5. Metal-catalyzed reduction of an acetylenic amine... 

Acetylenic Amines. Further modification of the phenylalkylamine side chain to include acetylenic moieties resulted in the discovery of a highly potent MAO inhibitor (107,108), pargyline (Eutonyl) ... 

Aziridines have been obtained from chloroallylamines by treatment with NaNH2 in liquid ammonia (Fig. 11). These reactions are highly dependent on the ratio amine-NaNH2 and in some cases the acetylenic amine becomes the major product (refs. 63, 64). 

See also Chapter 2 for discussion of irreversible MAO inhibition by acetylenic amines such as pargyline and deprenyl. 

Up to now only the reaction of lithiated diethylaminoallene with trimethylchloro-silane, resulting in (exclusively) Me3SiCH2C=C—NEt2, has been reported [104]. The metallation of the easily accessible 2-alkynylamines [6] can be brought about with BuLi /-BuOK in THF. Under suitable conditions free allenic amines can be obtained in a reasonable state of purity if the protonation is carried out with the lithium compounds (obtained from 2-alkynylamines and BuLi in THF, see Ref. [219]), the ratio of allenic and acetylenic amine is less favourable [9]. 

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