Reaction with 5-amino-3-substituted

Glutaraldehyde-mediated reaction with amino-substituted glass reaction with agarose cyclic imidocarbonate... 

Finally, trialkyl-substituted pyrazines 104 were prepared in a regiocontrolled manner from -nitroketones by reaction with -amino ketones <05OL5529>. 

The reactions of tri-ATZ-butylplumbyllithium with various phosphorus chlorides have been investigated. For example, reaction of the lithium compound with diphenylchlorophosphane afforded hexa-tert-butyldiplumbane and tetraphenyldiphosphane as the isolated products. Analogous reactions with -butyl-substituted phosphorus chlorides yielded (tri-A, 7-butylplumbyl)di- -butylphosphane or tri- z -butylplumbyl(amino)-, t -butylphosphane. These and other molecules were characterized by multinuclear magnetic resonance spectroscopic studies.24... 

The easy access of a hydroxy group of ninhydrin (254) to its substitution and the presence of the carbonyl groups makes this highly reactive compound an interesting starting point for cascade reactions with amino compounds. These have been mechanistically investigated with AFM on six different faces of 254 and strictly relate to the crystal packing [94]. 

By reactions of different 13,4-triazine derivatives, C-ribosyl imidazo[2,l-/][13,4]triazines <99JCS(P1)2929> and C-ribosyl 13.4-triazolo[3,4-/ [13,4]triazines <99JCS(P1)2937> have been synthesized as inhibitors of adenosine and AMP deaminases. Catalytic asymmetric aminohydroxylation with amino substituted 13,4-triazine and 133-tiiazine derivatives, as nitrogen sources, has been described <99AG(E)1080>. 

The addition-compounds of sodium bisulfite (or potassium bisulfite) with numerous sugars have199a been prepared in a pure state and have been shown to react with aromatic amines under conditions similar to those under which the free sugars react. -Substituted glycosylamines are formed, but the reaction with amino acids was not reported. 

Azomethine ylides are organic 1,3-dipoles possessing a carbanion next to an im-monium ion [ 12]. Cycloadditions to dipolarophiles provide access to pyrrolidine derivatives, useful intermediates in organic synthesis with stereo- and regiochem-ical control. Azomethine ylides can be readily produced upon decarboxylation of immonium salts derived from the condensation of a-amino acids with aldehydes or ketones. When they are added to C60, a fulleropyrrolidine monoadduct is formed in which a pyrrolidine ring is fused to the junction between two six-memberedrings of afullerene [13-15].Very importantly,functionalized aldehydes lead to the formation of 2-substituted fulleropyrrolidines, whereas reaction with AT-substituted glycines leads to AT-substituted fulleropyrrolidines (Scheme 1). 

Reaction with amino acid derivatives N-Protected amino acid esters substituted by I, Br, or OTs at the y-position undergo substitution reactions with lithium dialkyl cuprates without deteetable racemization. 

The reaction of carbodiimides with amino substituted boron clusters afford guanidinium-undecahydro-c/o50-dodecaborates in good yields. ... 

A good linear Qcr-relationship was obtained by Hashida et al. for azo coupling reactions with acetoacetanilides substituted in the p-position. The small influence of these substituents (p = —0.68) is understandable since the substitution does not take place at the benzene ring. An analogous result was found by Tuzalkova et al. for azo coupling reactions of 3 - and 4 -substituted l-phenyl-3 -amino- and l-phenyl-3-methytpyrazoline-5-ones. 

Most of the work reported with amino-substituted steroids has been concerned with the removal of the nitrogen function from the molecule. Interest has centred mainly on the peculiarities of the reaction between nitrous acid and steroidal primary amines. The naturally-occurring steroidal alkaloids have been studied mainly with a view to establishing their structures and usefulness as sources of nitrogen-free steroids, and are not included in the present survey. 

Imidazoles are electron-rich heterocycless and can undergo inverse electron demand Diels-Alder reactions. Particularly, amino-substituted imidazoles are good dienophiles and cyclize with electron-poor counterparts to provide cycloadducts. For example, intermolecular cycloadditions of 2-substituted imidazole 486 with various... 

Since transition-metal-carbene complexes with amino substitution at the carbene carbon atom are thermally very stable, their application as aminocarbene transfer reagents necessitates the use of high decomposition temperatures which, in many cases, is disadvantageous for the isolation of cyclopropylamines. Thus, for example, the cyclopropylamine 13 was not isolated from the reaction of an aminocarbene-chromium complex 12 with acrylonitrile in cyclooctane at 140°C instead, the respective decomposition product 15 was obtained in low yield.It is well known that cyclopropylamines readily undergo thermal ring opening so this result is not surprising. 

The linker was prepared starting from serine benzyl ester 68 according to Scheme 30. First, the hydroxyl function was protected as a silyl ether. The amino group was then reacted with phosgene to allow for further reaction with a substituted phenol (the educt). Finally, the benzyl ester was subjected to hydrogenolysis yielding unit 69, with the latter bearing a carboxylic acid function for attachment to the solid support to yield 66 ready for use in combinatorial synthesis. 

The mechanisms of the cascade reactions of amino-substituted imidazoles, pyrroles, and pyrazoles with 1,3,5-triazines have been studied using MP2/6-31 U-K //B3LYP/6-31G calculations in both the gas phase and in solution <05JOC998>. 

Pyridine IV-acylimines react with the amino-substituted cyclopropenium ion 43 in DMSO at 80°C to give cyclopropene imines, e.g., 45.172 In contrast, the reaction with thio-substituted cyclopropenium ion 44 under the same conditions gives jV,jV -dicyclopropenylidene urea derivative 46.173 Although the precise pathway involved in these reactions has not been established, the... 

Colman and Frieden (108) demonstrated in 1966 that acetylation of one amino group per subunit with acetic anhydride produces 80% inactivation. More extensive acetylation alters the degree of polymerization and certain kinetic parameters (276). Almost simultaneously, Anderson et al. (277) reported the reversible inhibition of GDH by pyridoxal 5 -phosphate and certain other aromatic aldehydes. The inhibition was attributed to formation of a Schilf base since reduction with NaBH4 results in irreversible inactivation. It was estimated that approximately one residue of -pyridoxyllysine had been formed per subunit. In 1969, Holbrook and Jeckel (278) inactivated the enzyme by reaction with a substituted maleimide and, subsequently, obtained the partial sequence of a tryptic peptide containing a modified lysine residue (Fig. 7). 

Amino-2-deoxyaldohexoses, 1-amino-l-deoxyketohexoses, and their V-alkyl and JV-aryl derivatives react with /3-dicarbonyl compounds, giving substituted (tetrahydroxybutyl)pyrroles. It is, most probably, a general reaction of 2-amino-2-deoxyaldoses and 1-amino-l-deoxyketoses which parallels the formation of (polyhydroxyalkyl)furans from nonnitrogenous monosaccharides. In the reactions with amino sugars in alkaline media, simpler pyrrole compounds lacking the tetrahydroxybutyl chain are also obtained. 

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