F-Amino effect

The reaction of 1,2-diazinamines with electrophiles is well studied while the substitution of amines-imines by nucleophiles is a highly nonstandard process. Nevertheless, even in the latter class new examples appeared since CHEC-II(1996) <1996CHEC-II(6)1>. A new section dealing with the so-called f-amino effect was added since many examples on 1,2-diazines have appeared since the mid-1990s. 

Amino acids as synthons for heterocyclic compounds, 64, 1 f-Amino effect, 14, 211, 65, 1 A-Aminoazoles, 53, 85... 

The f-amino effect—the unexpected reactions of a tertiary aniline bearing an ortho substituent leading to cyclization—was reviewed in this series in... 

However, the higher temperature needed to introduce the second amino function causes some dealkylation by way of the f-amino effect. 

Heterocycles by Ring Closure of Ortho-Substituted f-Anilines (The f-Amino Effect)... 

Gardette R, Krupa M, Crepel F Differential effects of serotonin on the spontaneous discharge and on the excitatory amino acid-induced responses of deep cerebellar nuclei neurones in rat cerebellar slices. Neuroscience 23 491-500, 1987... 

Hiatt JE, Eloyd TC, Katz PH, et al Eurther evidence of abnormal non-rapid-eye-movement sleep in schizophrenia. Arch Gen Psychiatry 42 797-802, 1985 Hicks TP, Krupa M, Crepel F Selective effects of serotonin upon excitatory amino acid-induced depolarisations of Purkinje cells in cerebellar slices from young rats. Brain Res 492 371-376, 1989... 

The dealkylation or ring opening of 1-f-aminoanthraquinones may thus be viewed mechanistically as another example of the <-amino effect and can be rationalized as shown below (214) -(206).110... 

The chemistry of A7-dialkylanilines is, for the most part, predictable. However, the presence of an ortho substituent can give rise to unexpected and interesting reactions of synthetic value. Although such reactions have been reported sporadically during the last 75 years, their usefulness is little appreciated possibly because the relevant observations are buried in the literature. In some cases incorrect structures have been assigned to products arising from such reactions simply because the effect of a f-amino group was not understood. 

In terms of this scheme, the value of the uydroi/ exch ratio would decrease as the substituent changed from f -amino to -nitro if k jk decreased. This change is in the expected direction since an electronegative substituent in the benzene ring would aifect step k which concerns a bond nearer the reaction centre more than it would affect step ki. An interesting experiment which Bender suggested in this connection would be the determination of the deuterium solvent isotope effects associated with proton transfer in the reactions of the intermediate. 

Sanderson, J., Wall, J. S. Donaldson, G. L. and Cavins, J. F. (1978) Effect of alkaline processing of corn on its amino acids. Cereal Chem., 204-213. 

Newman, E., Heslin, M.J., Wolf, R.F., Rsters, RW, and Brennan, M.F., The effect of systemic hyperinsulinemia with concomitant amino acid infusion on skeletal muscle protein turnover in the human forearm. Metabolism, 43, 70, 1994. 

Wang J, Fang Z, Gu A, Xu L and Liu F (2006) Effect of amino-functionalization of multi-walled carbon nanotubes on the dispersion with epoxy resin matrix, J Appl Polym Sci 100 97-104. 

The ten membered N-heterocycles have also attracted a lot of interest due to their structural appearance with various biologically interesting molecules like the alkaloid Dysazecine (Aladesanmi et al., 1983), Protopine (Xiao et al., 2008) (a potent antimalarial lead compound) as well as the nanomolar dopamine receptor antagonist LE300 (Mohr et al., 2006). Dunkel et al. (2010) reported a straight forward, microwave-assisted synthesis of tribenzo[b,d,f]- and pyridazino[d]dibenzo[b,f] azecines, employing the tert-amino effect. The desired compounds were furnished via an open-vessel microwave-assisted cyclization of corresponding triphenyl intermediates at 100-200 °C for 2-150 min. 

Physical Properties. Glycine is a colourless crystalline solid soluble in water. Owing to the almost equal opposing effects of the amino and the carboxylic groups. its aqueous solution is almost neutral (actually, slightly acidic to phenolphthalein) and glycine is therefore known as a neutral ampholyte. f It exhibits both acidic and basic properties. 

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