Benzyloxyamine

Other A-hydroxyimides have been obtained by reaction of benzyloxyamine with anhydrides, a process used many years ago with hydroxylamine itself. 

Benzyl methyl ketone, pi47 Benzyloxyamine, blOl... 

Synthesis of acid 129 starts from the commercially available 6-heptenoic acid (122), which upon reaction with (4S)-benzyloxazolidin-2-one (123) as the chiral auxiliary group yields the intermediate 124, hydroxymethylation of which affords compound 125. Hydrolysis of compound 125 followed by condensation with O-benzylhydroxylamine gives rise to the hydroxamate (126), which is then converted into (Claclam 127 via an intramolecular Mitsunobu reaction. Hydrolysis of the (Claclam 127 affords acid 128, which is subsequently formylated at the benzyloxyamine moiety to give the required intermediate acid (129) in quantitative yield, as depicted in Scheme 26. 

Fig. 17. MALDI-TOFMS of O-glycans enriched by a standard glycoblotting protocol using ammonium carbamate from human-milk OPN. Numbers represent the peaks attributable to O-glycans labeled with benzyloxyamine (BOA), and an asterisk indicates the internal standard. The glycan compositions listed in Table I were estimated from measured masses of the glycans by use of the GlycoSuite database. This figure is adapted from ref. 96.

The reaction mixture contained the substrate L-tyrosine. Benzyloxyamine was added to inhibit any secondary reactions catalyzed by the enzyme aromatic L-amino acid decarboxylase, an activity often present in these samples. Chromatograms of samples taken during an incubation are shown in Figure 9.1 B, a zero-time control with a single peak of tyrosine, and Figure 9.1C, after 20 minutes of incubation showing the peak of Dopa formed as a result of enzymatic activity. 

Reactions of carbonyl compounds with hydroxy-, methoxy, and benzyloxyamines are usually conducted in pyridine solution. To speed up the reaction the reaction mixture is heated at 60-100°C. The solvent (pyridine) is removed by evaporation in a flow of nitrogen, the sample is dissolved in ethyl acetate and an aliquot of the solution obtained is analysed by GC. 

Aminoxy chain-end-functionalized polybutadienes have been prepared by the reactions of PBDLi with halogen-containing benzyloxyamines. PBDLi (Mn = 990gmor, Mw/Mn=1.04) in heptane was reacted with 2,2,6,6-tetra-methyl-l-(2-bromo-l-phenylethoxy)piperidine at -78 °C as shown in eqn [33]. When this reaction was effected at room temperature, 73% of a dimeric polybutadiene product was obtained no dimeric product was observed when the reaction was carried out at -78 °C. The H NMR... 

The synthesis of N-benzyloxyaspartic acid (154) from bromoacid (153) and benzyloxyamine was complicated by formation of the p-N-benzyloxyamide of malic acid (156) as by-product (164) from the P-... 

In continuation of their research on N-hydroxypeptides Akiyama s group obtained the anilide hexapeptide with a 6-aminohexanoyl-3-(hydroxyamino)propanoyl sequence (225). This linear tri-N-hydroxy-amide bears a structural resemblance to the natural siderophores fer-rioxamines. Cyclic voltametry and UV spectrometry were used for the study of its iron complex. The key substrate was obtained by the addition of benzyloxyamine to / -nitrophenyl acrylate. 

Levine, R. J., Sato, T. L., and Sjoerdsma, A., 1965, Inhibition of histamine synthesis in the rat by a-hydrazino analog of histidine and 4-bromo-3-hydroxy benzyloxyamine, Biochem. Pharmacol. 14 139-149. 

Among the compounds which are active as inhibitors of the enzyme are benzyl-hydrazines and benzyloxyamines. both of which are isosteric analogues of phenyl-ethylamines (Fig. 6) Among the benzylhydrazines the decarboxylase inhibitor NSD1034 (Table 7) is also a potent inhibitor of the hydroxylase, and of the benzyloxyamines NSD loss is a potent example (Fig. 6X Benzyloxyamines act initially as competitive inhibitors. After prolonged exposure to the enzyme, however, the benzyloxyamine inhibition changes to a non-competitive type of interaction. 

Hyunsoo Han of the University of Texas, San Antonio has described Tetrahedron Lett. 2007, 48,7094) an improved protocol for the enantioselective conversion of primary aUy-Uc carbonates 16 to secondary amines 17. Rene Peters of ETH Zurich has used (Angew. Chem. Int. Ed. 2007,46,7704) a related procedure for the construction of aminated cpiater-nary centers. Mukund P. Sibi of North Dakota State University has devised J. Am. Chem. Soc. 2007,129, 8064) a catalyst for the conjugate addition of the benzyloxyamine 20 to acyl pyrazoles, and Claudio Palomo of the Universidad de Pais Vasco has found (Angew. Chem. Int. Ed. 2007, 46, 8054) that a simple diphenyl prolinol catalyst will effect enantioselective a-amination of aldehydes. 

Very recently, Deng and coworkers reported a highly enantioselective aza-Michael addition to enones with V-Boc-benzyloxyamine by employing a cinchona alkaloid-derived primary amine-TFA salt (Scheme 5.31) [59]. 

Anhydrous K-carbonate added slowly to a stirred soln. of N-hydroxyphthal-imide in dimethyl sulfoxide, then benzyl chloride added dropwise with stirring below 30°, and the product isolated after 24 hrs. stirring at room temp. N-benzyloxyphthalimide (Y 93.6%) refluxed 2 hrs. with 80%-hydrazine hydrate and ethanol benzyloxyamine (Y 90.5%). F. e. with HCl-hydrolysis s. T. Fujii, C. C. Wu, and S. Yamada, Chem. Pharm. Bull. 15, 345 (1967). 

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