Amines, cyclic tris amine

Compound (17) is synthesized by the treatment of the appropriate cyclic amine with tris(dimethylamino)phosphine at 100 °C, resulting in the elimination of three moles of dimethylamine. The products obtained are dependent on the number of methylene groups bridging the nitrogen atoms. When all four bridges are ethylene, (CH2)2, only (17a) is observed when all are trimethylene, (CH2)s, only (17b) is found. When there are two of each type, both tautomers are present. 

Tetrakis(dimethylamino)titanium converts DMF to tris(dimethylamino)methane (529 equation 236). This compound is also formed in the reaction of V-tetramethyloxamide with the titanium reagent, whereas amides which have a-CH bonds are converted to ketene aminals. Cyclic and spitocyclic compounds, containing the substitution pattern of a trisamino compound, are formed in the reaction of IVA -dialkylformamides or A/ -aryl-(VJV-dialkylformamidines with aryl isocyanates. Similar compounds, e.g. (530 equation 237), are produced in the reaction of imidazolines or lactamid-ines with isocyanates. 

Finally, the nucleophilic substitution reactions of mono-, di- and tri-chloronitrobenzenes 128 with N-methyl substituted cyclic tertiary amines 129... 

Detailed information on the copolymerization of cyclic trifluoropropylmethyl-siloxane trimer and octamethylcyclotetrasiloxane is also very limited in the open literature26 27 . Recently, preparation of various amine terminated (dimethyl-tri-fluoropropyl,methyl)siloxane oligomers with varying molecular weights and backbone compositions has been reported 69115 ll7). Table 11 shows various properties of the oligomers produced as a function of composition. These types of modification play very important roles in determining the solubility characteristics and hence the compatibility of resultant polysiloxanes with other conventional organic monomers... 

Succinimide is readily silylated by HMDS 2 to the N-silylated product 201, which seems, however, to be in equilibrium with the O-silylated derivative 202 a (cf the closely related reactive center in persilylated uridine 3) and reacts after 6-10 days at 24 °C with one equivalent of primary or secondary amines such as morpholine to give the crystalline colorless cyclic acylamidine 203 and HMDSO 7, even in the absence of any protective gas [33] (Scheme 4.12). The reaction is much faster on heating to 120 °C under argon. At these temperatures 201 and 202 a, and possibly also the acylamidine 203, are apparently partially O-silylated by HMDS 2 to the very sensitive 2,5-bis(trimethylsilyloxy)pyrrole 202b or to 2-tri-... 

Hofmann elimination reactions from hi- and tri-cyclic systems can, however, be used to create internal unsaturation without loss of a trialkyl amine as shown in Scheme 1.14 for the synthesis of the hexahydrothieno [ZjJazecine. 

The monocation tris(diethylether) ethylzinc is formed from diethyl zinc as a tetrakis(penta-fluorophenyl)borate salt.85 Longer-chain linear and cyclic ether complexes (2) of zinc alkyls have also been observed. The reaction between zinc dialkyls and primary amines gives a number of structurally diverse products dependent on the reaction conditions and the amine.86 The... 

It is known that the general structural characteristic of chelating ligands is a particular position of the donor atoms when the metal-cyclic polyhedra of coordination compounds are formed. The chelating N-donors are widely represented by Ai-(582), tri- (165,166,) tetra- (170-173), and penta- (174-177) amines (Sec. 2.2.4.2). Among diamine ligands, ethylenediamine (en) and its C- and N-substituted derivatives 585 are the most used [1] ... 

Fleischmann et al s 34 report cyclic voltammetry data for the oxidation of a series of aromatic hydrocarbons in a molten salt electrolyte, AlCl3-NaCl-KCl at 150°. Electrooxidation in this medium occurs at unusually low oxidation potentials. Tris-(p-substituted phenyl)amines, with the exception of tri (p-nitrophenyl) amine, yield very stable radical cations by all electrochemical criteria 380>S42 Mono- and bis-p-substituted triphenylamines, however, dimerize with rate constants ranging from 101 to 10s M 1 sec 1 to benzidines 176 (Eq. (237)), which subsequently are oxidized to the radical cations 177, whose ESR-spectra are observed. Dimerization is fastest with the p-N02 andp-CN-derivative, in accordance with HMO calculations, which predict the highest spin sensity in the p-position of these compounds 542 ... 

The reaction between aryl azides and lithiated aryl amines leads to tetrazenes, which give cyclic silatetrazenes with halosilanes (equation 7)17. Also, the new mono-, bis- and tris-silylamines 15-28 were obtained18-22. The hydrazine 16 was analyzed by electron and X-ray diffraction18. 

Meanwhile, PPS liberated phenol in a Tris buffer solution (16). Ethanolamine works similarly and the reaction proceeded first with the expulsion of sulfate by nucleophilic attack of amine followed by liberation of phenol, presumably through the formation of a five-membered cyclic intermediate (Figure 8). Both steps of S042- and phenolate liberation were found to be catalyzed by Mg2+ ion. In Figures 9 and 10 the data are shown for the liberation of phenol. Figure 9 indicates clear rate saturation attributable to complexation in acetonit-... 

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