Amines through reductive amination

Perhaps the advantage of the medicinal chemistry route lies in the flexibility of introducing different alkyl groups on the primary amine through reductive amination on 2-aminoethyl indole 10 and hence allows access to various N, N-dialkyl tryptamine derivatives for structure-activity relationship (SAR) studies. 

C Preparation of Primary, Secondary, and Tertiary Amines through Reductive Amination... 

Show how you might prepare each of the following amines through reductive amination PRACTICE PROBLEM 20.5... 

An interesting procedure has been proposed for the synthesis of amylose-b-PS block copolymers through the combination of anionic and enzymatic polymerization [131]. PS end-functionalized with primary amine or dimethylsilyl, -SiMe2H groups were prepared by anionic polymerization techniques, as shown in Scheme 56. The PS chains represented by the curved lines in Scheme 56 were further functionalized with maltoheptaose oligomer either through reductive amination (Scheme 57) or hydrosilyla-tion reactions (Scheme 58). In the first case sodium cyanoborohydride was used to couple the saccharide moiety with the PS primary amine group. 

To circumvent this problem, several methods have been developed (157). Probably, the most prominent method is treatment with sodium boro-hydride (0.1% in PBS, 30 minutes prior to staining). NaBILi is known to neutralize Schiff s bases through reduction of amine-aldehyde compounds into nonfluorescent salts. 

Dyestuffs in general, and azo dyes in particular, are likely to undergo. substantial primary biodegradation in an anaerobic environment through reductive cleavage of azo bonds into aromatic amines. Lipophilic aromatic... 

On the other hand, the production of desired compounds through reduction of starting material requires the electron donors to be oxidized (reductant). Alcohols are often used not only as a solvent but as the donor to produce useful compounds, e.g., anilines from nitrobenzenes,22) alcohols from aldehydes,23) and secondary amines from the corresponding Schiff bases.24) From the organic synthetic point of view, however, the separation of undesired products, aldehydes or ketones, from the alcohols is necessary unless subsequent reaction processes consume them25,26) or they are easily removed by distillation or other procedures. A recent report has shown that water acts as the electron donor and is converted into 02 in the photocatalytic regio-selective reduction of terpenes mixed with aqueous suspension of Ti02.27,28) It is notable that isolation of the desired product from the reaction mixture is simple in this type of photocatalytic reduction. 

Fig. 15.4-9 Prototype structu res of the Novartis TAM combinatorial libraries generated through reductive amination of selected aldehydes and secondary amines. The new structures for which examples are shown in (b) were designed to be similar to known monoamine CPCR ligands for which examples are shown in (a). Ligands, which are of the size of the endogenous ligands, are herein called simple - one-site filling...

Chiral amines. Synthesis of chiral amines from ketones through reductive amination with (-(-)- or (-)-norephedrine requires selective C-N bond cleavage. Sacrificial dissection of the chiron by periodate oxidation completes the operation. 

B Preparation of Aromatic Amines through Reduction of Nitro Compounds... 

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