V. F. Rudchenko

Asymmetrical nonbridgehead nitrogen-XXVI: Synthesis, configurational stability, and resolution of N,N-dialkoxyamines into antipodes

Abstract Alkoxyamines with tertiary N-alkyl substituents were chlorinated to N-chloro-N-alkoxyamines whose reaction with alcohols enabled synthesis of N,N-dialkoxyamines. The DNMR method was used to determine the barriers of inversion of these compounds. Alkaline hydrolysis ( 13 ) followed by subsequent reactions with R -(+)- and S -(−)-α-phenylethylamine yielded diastereomeric salts (+ 29 and − 29 ) whose crystallization and subsequent esterification resulted in optically active acyclic amines (− 13 and + 13 ) with the asymmetric center only at the N atom in the open chain.

Asymmetrical nonbridgehead nitrogen—XXIV: Complete separation into antipodes and absolute configuration of chiralic N-alkoxyaziridines

Optically active derivatives of 1 - methoxyaziridine - 2,2 - dicarboxylic acid have been obtained: the diethyl ester S-(− 1a) by kinetic enrichment under the action of 1-ephedrine; the diamines R-(+2d) and S-(−2f) by crystallization from 1-methyllactate; the diamide S-(−2g) by asymmetric inversion reaction at the N atom while heating in 1-methyllacetate. The basic possibility of 1-alkoxyaziridine reactions with retention of optical activity (ammonolysis and reduction with LAH4) has been demonstrated for S-(−1a) and R-(+1). 1-Methoxy - aziridine - 2,2 - dicarboxylic acid cis-ethyl ester 4 has been completely separated into antipodes 1R, 2S-(+4) and 1S, 2R-(−4) which under the effect of diazoethane afford diethyl esters R-(+1) and S-(−1) with optical purity of 96.2 and 93.8% (determined by PMR using a chiralic shift-reagent). On the basis of X-ray analysis of monoamides of 1 - methoxyaziridine - 2,2 - dicarboxylic acid ethyl ester and of salt +7 the trans-specificity of ammonolysis and hydrolysis of 1 and the absolute configurations of all the optically active derivatives obtained were established.

Asymmetric nitrogen - 70. geminal systems - 44. trialkoxy-amines(orthonitrites). Synthesis and properties

Abstract The chlorination of acyclic N,N-dialkoxyamines under the action of tert-BuOCl results in the formation of unstable N-chloro-N,N-dialkoxyamines which in situ react with sodium methoxide to give previously unknown trialkoxyamines (orthonitrites). The properties of the N-chloro-N,N-dialkoxy-and trialkoxyamines have been demonstrated to be similar to those of their carbon analogues: dialkoxyalkylchlorides and orthoesters, respectively.

Geminal systems. Communication 28 Alcoholysis of N-chloro-N-alkoxyamides and synthesis of N,N-dialkoxyureas

Conclusions1.N-Chloro-N-alkoxysulfonamides and N-chloro-N-alkoxyphosphoamides have chlorinating properties in the reaction with triethylamine in methanol.2.N-Chloro-N-alkoxyureas were synthesized for the first time, and from them previously unknown N,N-dialkoxyureas were obtained by nucleophilic substitution reactions.

Asymmetric nitrogen Communication 48. Geminal systems. communication 32 NH-dialkoxyamines: synthesis, mydroxy-and aminomethylation, nmr spectra, and configurational stability

Conclusions1.Alkaline hydrolysis of N,N-dialkoxy-N′,N′-dimethylureas gives NH-dialkoxyamines.2.N-Hydroxymethyl- and N-aminomethyl-N,N,-dialkoxyamines have been synthesized and their reactions with nucleophiles and electrophiles have been studied.3.The configurational stability of the N atom in NH-dialkoxyamines and their derivatives has been determined by NMR.

Geminal systems. Communication 29. Reactions of N-chloro-N-methoxy-N′,N′-dimethylurea with N-nucleophiles

ConclusionsIn the reaction of N-chloro-N-methoxy-N′,N′-dimethylurea with amines, a nucleophilic substitution of the chlorine atom at the N atom takes place to form N-alkoxyhydrazines, which are stable in the reaction with Me3N, pyridine, toluenesulfonamides, and give products of further transformations with Me2NH and MeONHMe.

1,2-rearrangement of N-Chloro-N-alkoxyamines in reactions with nucleophiles

ConclusionsWe discovered 1,2-rearrangements of N-chloro-N-alkoxyamines with migration of phenyl, alkyl, and carbomethoxy groups to the nitrogen atom.

N,N-DIALKOXY-N'-ALKYLUREAS

The chlorination of N-alkoxy-N′-alkylureas (1) by the action oft-BuOCl proceeds regiospecifically to give stable N-chloro-N-alkoxy-N′-alkylureas (2). The alcoholysis of2 leads to N,N-dialkoxy-N′-alkylureas (3). The alkaline hydrolysis of3 is a new, convenient method for the preparation of dialkoxyamines.

Synthesis and certain transformations of γ-nitrosoalcohols

The γ-nitrosoalcohols (II), (XII), and (IX), respectively, have been synthesized by acid-catalyzed hydrolysis of 2-alkoxyisoxazolidines (I), (Xa, b), (Xla, b), and 3-(dimethoxyamino)-3-trifluoromethylbutanol-1 (VIII). The nitrosoalcohol (II) readily rearranges into the oxime (III), and (XII) is converted into the diol (XIII) by oxidation with atmospheric O2 and denitrosation. For (IX) and (XII) ring-chain tautomerism with formation of 2-hydroxyisoxazolidines could not be detected by PMR spectroscopy.

N,N-Dimethoxyamine. A new methylating, aminating, and epiminating reagent

Electrophilically catalysed cleavage of the N–O bond of N,N-dimethoxyamine results in the formation of singlet N-methoxynitrenium ion, which aminates soft nucleophiles, methylates hard ones, and epiminates alkenes.