Fert-butyl amine

In the presence of excess monoalkylamine, carbonyl compounds in aqueous solution are in equilibrium with the corresponding imine. In most cases these imines cannot be isolated but they are reduced at a less negative potential than the carbonyl compound. Selective reduction of such equilibrium mixtures is a useful route to alkylamines from ketones in yields of 70-90%. The process fails with hindered ketones such as camphor and with bulky amines such as fert.-butyl amine. Overall the reaction has advantages of lower costs and simpler work-up compared to the use of cyanoborohydride reducing agents. In the electrochemical reaction, protonation of carbanion intermediates occurs from the more hindered side and where two isomeric products are fomied, the least hindered amine predominates [193]. 

Sodium chloride n-Ethyl-fert-butyl amine 40 0.1792 24... 

Monosubstituted chloramines have not received much attention. The reaction of A-chloro-fert-butylamine with di( < r -butyl)magncsium gives di(fert-butyl) amine in 10% yield.67 Butylmagnesium chloride and /V-chloromcthylaminc produce mostly methylamine by reduction and only 14% of A-methylbutylamine 68... 

As in the Japp-Klingemann reaction, when Z is an acyl or carboxyl group (in the case of R2CH—Z), it can be cleaved. Since oximes and nitroso compounds can be reduced to primary amines, this reaction often provides a route to amino acids. As in the case of 12-4, the silyl enol ether of a ketone can be used instead of the ketone itself. Good yields of a-oximinoketones (20) can be obtained by treating ketones with fert-butyl thionitrate. ... 

The nitrolysis of tertiary amines in the form of fert-butylamines and methylenediamines has been used to synthesize numerous polynitramine-based energetic materials. In these reactions one of the N-C bonds is cleaved to generate a secondary nitramine and an alcohol the latter is usually 0-nitrated or oxidized under the reaction conditions (Equation 5.15). The ease in which nitrolysis occurs is related to the stability of the expelled alkyl cation. Consequently, the fert-butyl group and the iminium cation from methylenediamines are excellent leaving groups. 

The nitrolysis of fert-butyl substituted amines with dinitrogen pentoxide in nitric acid solves many of these problems. However, these substrates are not always accessible via the usual condensation routes. The acidic reagents frequently used for these nitrolysis reactions are not always suitable for substrates with acid-sensitive or easily oxidized functionality. 

The conversion of substituted diphenylamines and triphenylamines to carbazoles at platinum anodes in CH3CN-Et4NC104 takes place if the intermediate cation-radical is fairly stable. Thus the anodic oxidation of (V-ethylbis(p-fert-butylphenyl)amine (87) gave 3,6-di-ferf-butyl-Af-ethyl-carbazole (88) in 15% yield152 [Eq. (72)]. 

There is direct evidence, from ir and nmr spectra, that the fert-butyl cation is quantitatively formed when ferf-butyl chloride reacts with AICI3 in anhydrous liquid HCl. In the case of alkenes, Markovnikov s rule (p. 1019) is followed. Carbocation formation is particularly easy from some reagents, because of the stability of the cations. Triphenylmethyl chloride and 1-chloroadamantane alkylate activated aromatic rings (e.g., phenols, amines) with no catalyst or solvent. Ions as stable as this are less reactive than other carbocations and often attack only active substrates. The tropylium ion, for example, alkylates anisole, but not benzene. It was noted on p. 476 that relatively stable vinylic cations can be generated from certain vinylic compounds. These have been used to introduce vinylic groups into aryl substrates. Lewis acids, such as BF3 or AIEta, can also be used to alkylation of aromatic rings with alkene units. 

The enantioselective total synthesis of (-)-epibatidine was accomplished in the laboratory of D.A. Evans." The key steps in the synthetic sequence included a hetero Diels-Alder reaction and a modified Hofmann rearrangement. The primary carboxamide was subjected to lead tetraacetate in fert-butyl alcohol that brought about the rearrangement and gave the corresponding A/-Boc protected primary amine in good yield. A few more steps from this intermediate led to the completion of the total synthesis. 

For halogenated pyrimidines, dehydrohalogenation competes with elimination of the hydride ion, as shown for 5-bromopyrimidine (173) in Scheme 64 (82JHC1285). Other examples are the amination of 4-tert-butyl-5-chloropyrimidine (174) and 2,4-di-fert-butyl-5-chloropyrimidine (175) with potassium amide in liquid ammonia (78RTC288). Some cine-substitution products (176 and 177) were also obtained (Scheme 65). From isotopic labeling studies, it was determined that the Sn(ANRORC) mechanism was not involved. 

Bohn s VO(acac)2/chiral Schiff base oxidation system was recently adapted by Ellman in the large-scale synthesis of a-branched amines [47]. Here, fert-butyl disulfide 26 was oxidized to the corresponding thiosulfinate 27 employing hg-and 23b. The oxidation was carried out using as httle as 1 mol % of catalyst giving fert-butyl ferf-butanethiosulfinate (27) with 91% ee (Eq.3). Further transformations of the thiosulfinate led to optically active amines in high yields. 

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