2,2 ,2"-Tris amine moiety

RW Frei, JF Lawrence, DS Le Gay. The analysis of some carbamte and urea herbicides by fluorime-try of their dansylated amine moieties. Analyst 98 9-18, 1973. 

Work published by Robert [76-78] have tried to fully establish a structure-reactivity relationship of amineboranes toward bleaching of mechanical pulps using molecular simulation. The literature suggests that the reductive strength of the amineboranes is proportional to the basicity of the uncomplexed amine moiety [61], According to this hypothesis, tertiary amines should have been the most efficient, but the experiments have shown otherwise (see Table 13.2). 

A variation of this method has been used to generate bis-benzimidazoles [82, 83]. The versatile immobilized ortho-phenylenediamine template was prepared as described above in several microwave-mediated steps. Additional N-acylation was performed by utilizing the initially used 4-fluoro-3-nitrobenzoic acid at room temperature exclusively at the primary aromatic amine moiety. A variety of amines have been used to introduce diversity by nucleophilic aromatic substitution. Cyclization to the polymer-bound benzimidazole was achieved by heating in a mixture of tri-fluoroacetic acid and chloroform, under reflux, for several hours. Individual steps at ambient temperature for selective reduction, cyclization with several aldehydes, and flnal detachment from the polymer support were necessary to obtain the desired bis-benzimidazoles. A set of thirteen examples was prepared in high yields and good purity [82]. 

A good structural and functional model of the heme/nonheme di-iron center of the active site of the prototype NOR has been developed and characterized by Karlin and co-workers.The complexes consist of a binucleating ligand with a tetradentate tris(2-pyridylmethyl)amine moiety tethered to a synthetic tetraarylporphyrin (with three 2,6-difluorophenyl meso substituents see Figure 11). As discussed above, the resonance Raman spectra of the oxidized compound show features in common with NOR supporting the assignment of the active site as oxo-bridged in the oxidized enzyme. 

The importance of a hydrogen bonding array is clearly demonstrated by the 2,2, 2"-tris(aminoethyl)amine moiety (2.63). This particular functional group has... 

Hakim, L Sabarudin, A. Oshita K. Synthesis of chitosan-based resins modified with tris(2-aminoethyi)amine moiety and its application to coiiection/concentration and... 

After finding the right combination for the diamine linkers, Yus et al. tried to determine whether it was compulsory to use two isoborneol-10-sulfonamide moieties. In this context, these authors have prepared the ligand depicted in Scheme 4.24 by reaction of the best amine linker, trani-cyclohexane-1,2-diamine, with camphorsulfonyl chloride and then with methanesulfonyl chloride, followed by reduction with AlH(i-Bu)2 and then hydrolysis.When this new ligand was involved in the enantioselective addition of ZnEt2 to acetophenone, the expected tertiary alcohol was obtained in excellent yield and enantioselectivity of 96% ee, as shown in Scheme 4.24. According to this result, the authors concluded that the second isoborneol unit seemed not to be necessary to obtain a high enantioselectivity. 

The formation of relatively stable species of the type (ArN)3N Mo N = N—MoN(NAr)3], in which further reduction of the N2 moiety is not very favored, can be prevented by the use of larger (ArN)3N triamido ligands. This led to the development of tris(amido)amine ligands... 

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