AMINES AND IMINES

Simandi, Z. Szeverenyo, and E. Budo-Zahonyi, Irtorg. Nuclear Chem, Letters, 1975, 11, 773. 

Significant i.r. frequency shifts in N—H mode have been observed in ML, C2 complexes [M = Co or Ni L = 5-aminoimidazole X = Br, I, NO3, MeC02, NCS, and S04 m = 1,2, or 4). Thermodynamic data have been obtained for the reaction of imidazole and x-methylimidazole (x = 1,2,4, or 5) with aquocobaltamine in aqueous solution. The complex [(tren)Co(/i-peroxo-/t-hydroxo)Co(tren)](C104)3,3H20 has been prepared by the oxygenation of [Co(trenXH20)2] in alkaline solution.  

Macrocycles. The influence of solvents and added solute molecules on the nature of associative species observed in solutions of the sodium salt of cobalt(ii)tetrasulpho-phthalocyanine has been investigated by electronic absorption spectrophotometry. Isolation of LCo2Br2,MeOH [LH2 = macrocyclic tetrakis SchifT base (10)] and its oxidation by Br2 to form LCo2Br3,2H20 has been reported. The crystal structure of the LCo2Br2,MeOH complex consists of a dinuclear unit with the two cobalts separated by 3.158(2) A and each cobalt is in an identical pseudo-square-pyramidal 

Zehnder, U. Thewalt, and S. Fallat, Helv. Chim. Acta, 1976,59, 2290. 

Hoskins, R. Robson, and G. A. Williams, Inorg. Chim. Acta, 1976,16,121. 

The decomposition reactions of amines are potential sources of the amino radicals. However, the reactions are complex and relatively little understood processes, and in most cases even the nature of the primary step is open to question. Quantitative studies are scarce. 

An early study of the pyrolysis of methylamine reported the decomposition to follow a homogeneous first order path (500-670° C), viz. 

Compound log A (5ec ) E, or Aflt (kcal.mole ) ASt (eu) Solvent or state 

The rate parameters are listed in Table 24. With the tertiary isomer of the W-nitro-iV-fluoroamine the large positive A5 with ethylcyclohexane solvent is consistent with the radical split mechanism whereas AS = —4.6 eu with CCI4 indicates that the cyclic transition state mechanism predominates. 

The thermolysis of cyclopropylamine affords NH3 and 7V-propylidenecyclo-propylamine the reaction is homogeneous, probably unimolecular, and the kinetics obey the first-order expression, k = 10 exp (—58,090/i r) sec . The reactive intermediate is probably propylidenimine which can be formed via a biradical intermediate or by a concerted process 

Secondary amines show only a single NH stretching band in the 3500—3200 cm region, which is also subject to small changes on hydrogen bonding, and imines absorb in very much the same region. 

The NH deformation in these compounds is too weak to be of any real value for identification purposes, although there appears to be an enhancement of the intensity in a limited number of cases. As with primary amines, C—N linkages of aromatic compounds can be identified, whereas the corresponding aliphatic materials show weaker absorptions which are more variable in position. 

Tertiary amines are extremely difficult to identify spectroscopically. The C—N stretching band in aromatics can be identified in some cases, but there is no satisfactory correlation for aliphatic materials. The possibility of identification of the CH3 —N group is also discussed. 

All the above intensify, broaden and move to lower frequencies on association. 

Secondary amines. 1650-1550 cm (medium aryl, weak alkyl) 

The tertiary amine (CFa)jN [CF2]6 CFa has been prepared by electrochemical fluorination of AW-dimethyl-aniline, -pentafluoroaniline, and -cyclohexylamine. Perfluoroalkyl-A fluoroamines have been obtained in very low yields by electrochemical fluorination of trifluoroacetonitrile 

It has been revealed in a paper dealing with n.m.r. studies of inversion at nitrogen that synthetic routes to the saturated heterocycles (7)—(10) have been discovered, but no details were given.  

An account of the chemistry of bistrifluoromethylamino-compounds, based on a review lecture delivered in 1968, has been published. JV-Bromo-bistrifluoromethylamine has been used to synthesize the acetylenes (CFajjNCICH, (CFs),N-CiC-N(CF,)2, (CFj) N-ClCCF3, and (CFsjjN CiCMe, the chemistry of which is discussed in Chapter 2 (p. 48) an unsuccessful attempt to prepare the silane (CFs)2N CH2-SiMes from the mercurial [(CF3)2N]2Hg and iodomethyltrimethylsilane has also been mentioned previously (see p. 92). Dehydrobromination of the adducts formed 

Details of the synthesis of a range of polyfluoroalkenylamines and per-fluorocyclobulenylamines via treatment of fluoroalkenes with lithium derivatives of secondary amines e.g. CFjiCFj + LiNBuj — CFaiCF NBuj)  

N-(2-Chloro-l,l,2-trifluoroethyl)diethylamine, which is readily prepared from chlorotrifluoroethylene (EtjNH + CFa CFCI- EtjN-CF -CHFCI), has seen more use in the conversion of steroidal alcohols into the corresponding monofluorides with the synthesis of 11 j8-fluoro-counterparts of 1 loi-hydroxy-19-nor-steroids. Furthermore, the ll)3-chloro- and -bromo-analogues have been obtained by treatment of the 1 la-hydroxy-steroids with the a-fluoroamine reagent in the presence of lithium chloride and bromide, respectively, e.g. 

---

Spelling of amonium, imonium, and iminium indicates derivation from amine and imine onium salts. 

Cohen F, Overman LE (1998) Planar-chiral cyclopalladated ferrocenyl amines and imines as enantioselective catalysts for allylic imidate rearrangements. Tetrahedron Asymmetry 9 3213-3222... 

The Nitrogen Analogs of Enols and Enolates En amines and Imine Anions... 

In addition to alkenes and alkynes, allenes have attracted considerable interest due to their unique reactivity and multireaction sites. Therefore, transition-metal-catalyzed nucleophilic addition reaction of amines and imines to allenes has been extensively studied to prepare biologically important amines and nitrogen-heterocycles.31,31d... 

The asymmetric aza-Claisen rearrangement of allyl imidates, (86) (87), has been shown to be catalysed by homochiral cationic palladium(II) complexes, and a series of enantiopure cyclopalladated ferrocenyl amines and imines have been... 

Solid tertiary amines and imines may be quantitatively alkylated by gas-solid and solid-solid techniques. Methylation of quinuclidine (176) to give the methoiodide 177 is achieved waste-free by exposure of 176 to a stoichiometric amount of methyl iodide vapor (Scheme 23). Difficulties with the disintegration of the crystals of 177 from those of 176 (reaction step 3) are overcome by ultrasound treatment from a cleaning bath at 20 °C [22]. Numerous applications of this technique to tertiary amines can be envisaged. However, solid Troeger s base (with interlocked layers, i.e., no possibility for molecular migrations) is not alkylated by methyl iodide vapor unless an excess of the vapor is applied to induce intermediate (partial) liquefying of the solid [22]. 

The single largest use of ammonia is its direct apphcation as fertdizer, and in the manufacture of ammonium fertilizers that have increased world food production dramatically. Such ammonia-based fertilizers are now the primary source of nitrogen in farm soils. Ammonia also is used in the manufacture of nitric acid, synthetic fibers, plastics, explosives and miscellaneous ammonium salts. Liquid ammonia is used as a solvent for many inorganic reactions in non-aqueous phase. Other apphcations include synthesis of amines and imines as a fluid for supercritical fluid extraction and chromatography and as a reference standard in i N-NMR. 

Similar reaction occurs with amines and imines the decomposition is rapid ... 

Some aliphatic amines and imines and their nitrated derivs were prepd and investigated before and during WW II by Division 8 of NDRC... 

Amines as Rocket Fuels. See Refs 6 8 and Addnl Refs e,g,i,k 1 under Amines and Imines... 

Aliphatic amines and imines, nitrated derivs 1 A124... 

Cyclizations of alkenic amines and imines using organoiron complexes to generate bicyclic 3-lactams are discussed in Chapter 3.1 of this volume. Examples of heterocyclizations of alkenic NA/-dialkylamine and pyridine derivatives to form cyclic quaternary ammonium salts are cited in the Staninets review.Ic A cyclization of an enol thioether has been used to generate a thiazolidine intermediate used in cephalosporin synthesis (equation 131).262... 

These compounds, according to the US NavOrdLab Memorandum 10068, 3/24/1949, are characterized by low mp, good heat stability and moderate sensitivity Aliphatic Amines and Imines, Nitrated Derivatives. A number of these compds are of interest in the field of explosives and are discussed under the individual compds, such as amino methane, aminoethane, amino-guanidine, etc... 

The equilibrium between carbonyl compound, amine and imine is metal-ion dependent and the position of the equilibrium may be perturbed by the co-ordination of any of the components to a metal ion (Fig. 4-21). 

Fig. 9. Relative stabilities of the associated amine and imine forms of adenine tautomers.

TABLE 13. Neurotropic activity of germyl-substituted amines and imines ... 

---