52601-78-2

Homotopic 1,10-diaza-18-crown-6 derivatives with two, four, and six chiral centers have been prepared in optically active form from diethanolamines via a cyclization reaction with tosylates 39 and 48.The requisite optically active diethanolamines were prepared from chiral cyanohydrins and chiral ethanolamines by a one-pot Grignard-transimination-reduction or a one-pot reduction-transimination-reduction procedure.Yields were strongly affected by the size of the substituents α to the nitrogen atom.The stereoselectivity of the diethanolamine synthesis was found to depend on the configuration of the ethanolamine used.

A series of cyclic mono-, di- and poly-aza compounds has been synthesised in moderate to good yields by reaction of p-toluenesulfonamide and either α,ω-ditosylates or α,ω-dichlorides.

The synthesis and complexation properties of polycarboxylate diaza crown ethers based on R,R-(+)-tartaric acid are described.Cesium carbonate mediated macrocyclization of a bis-tosylamide precursor with a bis-tosylate precursor provided the protected crown ethers.Photochemical deprotection of the tosylamides and hydrolysis of the carboxamides yielded dicarboxylic and tetracarboxylic acid derivatives of 1,10-diaza-18-crown-6.N-Methylenecarboxylate (N-acetate) derivatives were prepared by N-alkylation with bromoacetic acid.The synthetic and purification procedures developed provide samples of the ligands in a metal-free form.Acidity and stability constants for complexation of alkali metal, alkaline earth, late- and post-transition metal cations were determined by potentiometric titration.The ligands form complexes which show enhancement of stability by charge-charge and chelate interaction with the carboxylates.In comparison with crown ether polycarboxylates these aza crown ethers showed a selectivity for softer metal ions relative to alkali and alkaline earth metal ions.N-Methylenecarboxylate chelate ligands were found to bind almost all types of metal ions, due to a highly co-operative array of charge-charge, chelate and crown ether interactions.

A method is proposed for the production of di- and polyazacrown ethers by the condensation of bissulfonamides with dibromides or ditosyloxy derivatives in a two-phase aqueous alkali-toluene (benzene) system.The optimum concentration range for the substrate and the alkylating agent is 0.017-0.1 M.The catalytic activity of the quaternary ammonium salts decreases in the order (Bu)4NI > (Bu4)NBr > (Bu4)NCl > (Bu4)NHSO4 > (C2H5)3C6H5CH2NCl >> (Et)4NI > (Et)4NBr.The highest yields of te 12-membered azacrown ethers are obtained in the presence of lithium hyroxide, and the largest yields of the crown ethers with larger ring sizes are obtained in the presence of sodium or potassium hydroxide, and this is probably due to the matrix effects of the cation.

A facile procedure is proposed for the preparation of azacrown ethers and cryptands by condensation of dibromides or ethylene glycol bis(toluene-p-sulphonate)s with acyclic bis(sulphonamide)s or with bisdiazacrown ethers, respectively.The reaction was carried out in a two-phase system of aqueous alkali-toluene (benzene)in the presence of quaternary ammonium salts as phase transfer catalysts.The catalytic activity decreased in the sequence: Bu4NI ca.Bu4NBr > Bu4NCl > Bu4NHSO4 > Et3NCH2C6H5NCl.Maximum yields of twelve-membered azacrown ethers are obtained when lithium hydroxide is used, while crown ethers of larger size are observed in the presence of sodium or potassium hydroxides; this may be due to a template effect.

A one-step, general procedure for a variety of N-tosyl aza macrocycles (including aza-crown ethers, pyridino- and bipyridino-aza-crown analogues, and azacyclophanes), by reaction of appropriate bis(halomethyl) precursors with tosylamide monosodium salt (TsNHNa) in N,N-dimethylformamide, is described.In polymethyl-substituted 2,11-diazacyclophane systems, the methyl substituents play an important role in inducing stereospecific ring closures.Thus, coupling of 1,4-bis(chloromethyl)-2,5-dimethylbenzene (15b) with TsNHNa produced only one of the two possible diastereomeric dimers, to which chiral structure 16db was assigned by means of the chiral Eu(dcm)3 shift reagent.This stereochemical assignment was confirmed by a single-crystal X-ray study on 16d.Detosylation of N-tosyl aza macrocycles to the free polyamino macrocycles by reductive (Na-NH3) or hydrolytic (90percent H2SO4) methods, followed by N-methylation (CH2O-HCO2H), was also accomplished in excellent yield.The 1H NMR spectra of 2,11-diazacyclophanes and 2,11-diaza(2,6)pyridinophanes are discussed in terms of conformation and conformational mobility.

Modification of the Richman and Atkins method for preparation of symmetric and nonsymmetric bis-(p-toluenesulphonyl) diazacoronands is reported.The one-pot transformation of these compounds into N,N'-dimethyl diazacoronands is also described.

Reactions of p-toluene/benzenesulphonamides with p-toluenesulphonate ester of diols under liquid-liquid and solid-liquid phase transfer (PT) conditions give cyclic N-p-toluenesulphonyl or N-benzenesulphonyl derivatives with 1:1 and/or 2:2 stoichiometries.Thus, the cyclic system containing N and/or O as heteroatom(s) have been procured usimg this procedure.

A variety of title compounds (azacrown ethers, pyridino-azacrown analogues and azacyclophanes) have been synthesized in moderate to good yield by coupling appropriate bis(halomethyl) or bis(tosylate ester) precursors with tosylamide monosodium salt.A revised mechanism is proposed.

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