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We have a l r eady shown [1] that the ra te of a b a s e c a t a l y z e d condensat ion of acetaldehyde with Aand Ab is [N-sa l iey l ideneglyc ina to]eobal ta te ( I I I ) ions (ia) and (Ib) unsubst i tuted in the a roma t i c r ing is l imi ted by the abs t r ac t ion of ~ -0 ro t on of the glycine f r agment . In the p r e s e n t work we studied the condensat ion of sodium Aand2`-bis [N-3-methylsa l icyl ideneglycinato]cobal ta te( I I I ) Na (IIa) and (IIb), and the r a c e m i c po tass ium (A, A) bis [N5-bromosal ieyl idenegiycinato]cobal ta te(17I) with acetaldehyde. In (II) the CH 3 group s t e r i ca l ly sMelds f r o m an a t tack at the side of the phenolic oxygen atom, and has a r e l a t ive ly smal l inductive effect [2], while in (17I) the e l ec t ronega t ive b romine a tom is m a x i m a l l y r emoved f r o m the react ion cen te r and can only exe r t an e lec t ronic influence on it.

1 We synthesized the complexes: K (+)530- and (−)530-bis[N-salicylidene-(S-valinato)]cobaltate(III), K (+)530- and (−)530-N-salicylideneglycinato-[N-salicylidene-(S-valinato)]cobaltate(III), and K (+)530- and (−)530-bis[N-3-methylsalicylidene-(S-alaninato)cobaltate(III), and characterized them via the NMR and UV spectra and the optical rotation dispersion curves. 2. A study was made of the epimerization of the complexes under the influence of bases in water and active carbon in ethanol, and it was shown that for the salicylaldehyde derivatives the most favorable are the isomers with the absolute configuration of the complexes of the (+)530-series and an absolute R configuration of the amino acid. 3. In the alkylation of the glycine fragment of K (+)530 and (−)530-N-salicyIideneglyeinato-[N-salicylidene-(S-valinato)]cobaltate(III) with acetaldehyde the asymmetric yield and the ratio of the threo: allo forms of threonine both depend on the degree of epimerization of the S-valine fragment in these compounds, which testifies to the presence of the mutual effect of the asymmetric centers in the studied complexes. 4. From the circular dichroism curves of the (+)530-bis[N-salicylideneglycinato]cobaltate(III) ion in the UV region it was established that it has the absolute λ configuration, which is in agreement with the data obtained for the complexes of the (+)530-series by chemical methods.

1. In aqueous solution the Mannich reaction proceeds according to an ionic mechanism, proposed by Lieberman and Wagner. The reaction mechanism remains the same in acid and alkaline medium. 2. The basicity constants and rate constant of cleavage of the C-C bond of 1-diethylamino-2-methyl-2-nitropropane were determined, along with the entropy and enthalpy of activation of cleavage of the C-bond for this compound.

1. The kinetics of the decomposition of 1-diethylamino-2,2-dinitropropane in solutions of H2SO4 was studied at various temperatures and acidities of the medium. Replacement of the leaving group with (CH3)2· by leads to a 6000-fold increase in the rate of decomposition. 2. The dissociation constants of the conjugate acids of 1-dimethylamino-2-methyl-2-nitropropane, 1-diethylamino-2-methyl-2-nitropropane, 1-diisopropylamino-2-methyl-2-nitropropane, and 1-diethylamino-2,2-dinitropropane in acetonitrile at 25° were determined. 3. The absorption of theβ-nitroamines studied in the region of 240–360 nm characterizes the presence of some intermolecular interaction between the amino and nitro groups in these compounds.

1. The decomposition of Mannich bases occurs according to the mechanism that we had demonstrated earlier. The decomposition constants were determined for 1-methylamino-2-methyl-2-nitropropane, 1-din-propylamino-2-methyl-2-nitropropane, 1-dimethylamino-2-ethyl-2-nitrobutane, and 1-diethylamino-2-ethyl-2-nitrobutane. 2. The deciding role of steric factors in the decomposition of Mannich bases was demonstrated.

1. By the method of “competing” reactions relative reactivities were determined in the nitration of a series of aromatic sila-hydrocarbons in which the aromatic ring occupied various positions with respect to the silicon atom. 2. The results confirm the presence of conjugation between the Si-C bond and the aromatic ring in trialkylbenzylsilanes.

1. The kinetics of the decomposition of 1-dimethylamino-2-methyl-2-nitropropane and 1-diisopropyl-amino-2-methyl-2-nitropropane in water at various temperatures and pH of the medium was investigated. The dissociation constant of the conjugated acid of 1-dimethylamino-2-methyl-2-nitropropane was determined at 25° andμ=0.1. The dissociation constant of the conjugated acid of 1-diisopropylamino-2-methyl-2-nitropropane and the true rate of decomposition of this compound at 25° were estimated on the basis of the correlation equations. 2. The values of the true rate constants of the decomposition of the nonprotonated form of 1-dimethylamino-2-methyl-2-nitropropane and l-diethylamino-2-methyl-2-nitropropane were determined at various temperatures. The values of the enthalpy and entropy of activation of cleavage of the C-C bond in 1-dimethylamino-2-methyl-2-nitropropane and l-diethylamino-2-methyl-2-nitropropane were determined.

1. The resolution of potassium D,L-bis-(N-salicylideneglycinato)cobaltate (III) with brucine was accomplished. 2. The reaction of either the D- or L-forms of potassium bis-(N-salicylideneglycinato)cobaltate with acetaldehyde under the influence of bases leads to the asymmetric synthesis of threonine (45%) and allothreonine; the R-form of the amino acid predominates for the D-form of the complex, and the S-amino acid predominates for the L-form.

1. A study was made of the decomposition kinetics of 1-piperidyl-2-methyl-2-nitropropane and 1-morpholyl-2-methyl-2-nitropropane in 0.1 N KOH solution. 2. The constants of the true decomposition rates of these compounds at 25° were determined, as well as the enthalpy and activation entropy for cleavage of the C-C bond. 3. The ionization constant of the conjugated acid 1-morpholyl-2-methyl-2-nitropropane was determined; on the basis of correlation equations, the value of the ionization constant of 1-piperidyl-2-methyl-2-nitropropane was estimated. 4. The contribution made by the polar effect to the previously observed change in the decomposition rates of N-alkyl-β-nitroamines is slight.