Amines synthesis from azides

A similar microwave-assisted cyclization in the presence of ammonium acetate of an a-ketoamide, obtained by acylation of an a-aminoketone, was recently described for the synthesis of the antifungal agent Nortopsedin D [46]. The problem of the instabiUty of the a-amino ketones was successfully resolved by in situ acylation of the amine derived from Staudinger reaction of the azide 50 with a phosphine (Scheme 16). This ketoamide was... 

The synthesis of secondary amines from azides is efficient in terms of chemos-electivity [57] and has found valuable applications in the preparation of diamines [58,59], m-alkylaminoboronic esters [60], and in Diels-Alder-based amination reactions [61]. A convenient general route to open-chain polyamines, which play major roles in cellular differentiation and proliferation, has also been developed using the reductive alkylation of aliphatic aminoazides by (co-halogenoalk-yi)dichloroboranes as a key step [62] (Scheme 21). 

Phenylethylamine has been made by a number of reactions, many of which are unsuitable for preparative purposes. Only the most important methods, from a preparative point of view, are given here. The present method is adapted from that of Adkins,1 which in turn was based upon those of Mignonac,2 von Braun and coworkers,3 and Mailhe.4 Benzyl cyanide has been converted to the amine by catalytic reduction with palladium on charcoal,5 with palladium on barium sulfate,6 and with Adams catalyst 7 by chemical reduction with sodium and alcohol,8 and with zinc dust and mineral acids.9 Hydrocinnamic acid has been converted to the azide and thence by the Curtius rearrangement to /3-phenyl-ethylamine 10 also the Hofmann degradation of hydrocinnamide has been used successfully.11 /3-Nitrostyrene,12 phenylthioaceta-mide,13 and the benzoyl derivative of mandelonitrile 14 all yield /3-phenylethylamine upon reduction. The amine has also been prepared by cleavage of N- (/3-phenylethyl) -phthalimide 15 with hydrazine by the Delepine synthesis from /3-phenylethyl iodide and hexamethylenetetramine 16 by the hydrolysis of the corre-... 

An alternative to the azide synthesis is the Gabriel amine synthesis, which uses a phthalimide alkylation for preparing a primary amine from an alkyl halide. Imides (-CONHCO-) are similar to ethyl acetoacetate in that... 

Secondary amines from azides. The reaction of alkyldichloroboranes with azides leads to secondary amines directly. This process has been incorporated into a polyamine synthesis. Note that the dichloroboranes can be prepared from organobis (diisopropylamino)boranes. ... 

The yield of a 1-adamantamine decreases in the presence of a more polar compound, such as cyclohexanol, which adsorbs more readily onto TiOj particles than 1-azidoadamantane. Because azides can be produced readily from alkyl halides, photoreduction of azides on SC provides an easier alternative to amine synthesis [151]. 

Sigurdsson et al. developed the synthesis of isocyanates from aliphatic amines [21]. Thus, the reaction of an aliphatic amine with trichloromethyl chloroformate (diphosgene) in the presence of Proton Sponge (1) (2 equiv.) at 0°C gave isocyanate in 81% yield. Azide isocyanate was synthesized from azide amine by means of a similar procedure by Keyes et al. [22] (Scheme 8.8). 

The possibility of practical synthesis of azides from amines, which emerged about a decade ago [123], recently attracted considerable attention [107,112] and was successfully applied for the syntheses of mono- and disaccharide analogs of Dau bearing the azidopyranose moiety. 

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