Monoaza crown

Blackburn C, Bai M, LeCompte KA et al (1994) Lithium responsive fluorophores derived from monoaza-12-crown-4 and coumarin. The influence of a methoxy side-arm on photophysical properties. Tetrahedron Lett 43 7915-7918... 

The polarographic experimental and calculated curves of complex formation with the following ligands N, Ai -bis(2-pyridyl methyl)- ,2-diaminoethane [118], picolinic acid [119], Ai-(2-hydroxyethyl)ethylenedi-amine [120], 1-hydroxyethylenediphospho-nic acid [121], and Ai-(2-hydroxyethyl)imi-nodiacetic acid [122] was used for modeling the Cd(II)-Kgand systems. The stoichiometry and stability constants of formed complexes were evaluated. The same method was used for determinations of stability constants of Cd(II) complexes with monoaza-12-crown-4 ether in aqueous solution in the presence of an excess of sodium ions [123]. 

A spironaphthoxazine derivative incorporating a monoaza-12-crown-4 entity at the 5 -position has been prepared by Kimura el al.19 It is a light-resistant, cation-complexable photochromic compound. 

Methylisophthaldialdehydc, 703 Methyl vinyl ketone, 88, 541 Monoaza-12-crown-4, 262 Monoaza-15-crown-5, 176 Monoaza-crown macrocycles, 173-185... 

When certain long polyethyleneoxy side arms were present, formation of monoaza-15-crown-5 and 18-crown-6 derivatives by cyclization sometimes proved difficult. In such cases,the parent compounds were N-alkylated to give the desired lariat ethers. The parent compounds were obtained from the N-benzyl derivatives, prepared as described previously, which were hydro-genolyzed to the parent macrocycles. Such a procedure was used to prepare a number of monoaza-12-crown-4 derivatives as well (13). 

Other monoaza-12-crown-4 derivatives were prepared by using the cyclization method developed by Calverley and Dale (14, 15). This method involves reaction between a primary amine and tetraethylene glycol diiodide. 

Nitro-2- l,4,7-trioxa-lO-azacyclododec- 10-ylmethyl)phenol, 9CI. - 2-Hydroxy-5-nitrobenzyl)monoaza- 12-crown-4 [96927-45-6]... 

Chiral monoaza-crown ethers containing glucose units have been applied as phase-transfer catalysts in the Michael addition of 2-nitropropane to a chalcone to give the corresponding adduct in up to 90% ee. (Eq. 4.138).202... 

E. F. J. de. Vries, L. Ploeg, M. Colao, J. Brussee, A. van der Gen, Enantioselective Oxidation of Aromatic Ketones by Molecular Oxygen, Catalyzed by Chiral Monoaza-Crown Ethers , Tetrahedron Asymmetry 1995, 6, 1123-1132. 

Fig. 12 Left. ICT-PET probe 34 with a small and rigid spacer (thick black), decoupling the PET active donor = receptor unit from the 7c-conjugated ICT fluorophore. Middle and right probes 35 and 36 combining a conventional ICT and a virtually decoupled ICT process with two identical receptor units (35, for Hg2+) and two different receptor units (36, tetraoxa monoaza crown for Na+ and dithia monooxa monoaza crown for Ag+). For color code, see Fig. 10...

Methods are now available for the synthesis of N substituted monoaza-crowns with >N(CH2CH20)jj-H sidearms (31). Such molecules could be attached to chloromethylated polystyrene as indicated in references 35-50. 

Figure 3. Salt effects on cloud points of N-alkyl monoaza crown ethers and the corresponding open chain derivatives (from Kuo and Okahara, Ref. 22. 1983)...

Syntheses of N-alkyl aza crown ethers have been based on a modified protocol previously investigated for similar compounds [5,55,56]. The reaction used for S5mthesizing recyclable monoaza crown ethers in this study is illustrated in Scheme 10.1 [57]. Eight monoaza crown ethers were successfully synthesized... 

Figure 10.5 Effect of N-alkyl group variation of monoaza crown ethers on extraction efficiency of [C4CjIm][Tf2N] containing N-alkyl aza-18-crown-6 (0.1 M). (Reproduced from the American Chemical Society from Luo, H. M., Dai, S., Bonnesen, R V., Anal. Chem., 76, 2773-2779, 2004. With permission.)...

Matsushima, K., Kobayashi, H., Nakatsuji, Y., Okahara, M., Rroton driven active-transport of alkali-metal cations by using alkyl monoaza crown ether derivatives, Chem. Lett., 701-704, 1983. 

Various alkyl-substituted crown ethers have been prepared by cyclic addition across a double bond (e.g. bromination (77S854) or oxymercuration (80CC925)). Similarly, displacement of oligoethylene glycol dichlorides by cyanamide yields V-cyano monoaza crown ethers (81TL4105). 

Synthesis of monoaza crown ethers from A, A -di[oligo(oxyalkylene)]amines and oligoethylene glycol di(p-toluenesulfonates) or corresponding dichlorides, H. Maeda, S. Furuyoshi, Y. Nakatsuji and M. Okahara, Bull. Chem. Soc. Jpn., 1983, 56, 212. 

Okahara and coworkers used the diol plus arylsulfonyl chloride procedure to prepare the crown ethers (Kuo et al., 1978). This method is convenient for preparing the A -alkyl-substituted monoaza-crowns as shown in the following reaction. 

The yV-alkyl-substituted azadiol was treated with an equimolar amount of tosyl chloride and excess alkali metal hydroxide in an aprotic solvent (powdered NaOH, dioxane, room temperature, 3 hr) to give a 60% yield of the monoaza-crown (Kuo et al., 1978). Template effects are important in this cyclization reaction, so sodium hydroxide was used for aza-15-crown-5 and potassium hydroxide for aza-18-crown-6. The intramolecular ring-closure process is the result of the initial formation of a tosylate by the reaction of one alkoxide anion with tosyl chloride followed by displacement of the tosylate leaving group by the second alkoxide anion. The pure monoaza-crowns were isolated from their metal ion complexes by thermolysis under reduced pressure (Kuo et al., 1980). 

A monoaza-crown with a butylene bridge and containing two hydroxy groups on chiral ring carbon atoms was prepared by a similar process (method A-4) (Lukyanenko et al., 1988). 

A more complicated diol was used by Bartsch and coworkers to prepare monoaza crowns with no substituent on the ring nitrogen atom and with a hydroxymethyl substituent on a macroring carbon atom (method C-5) (Son et al., 1984, 1985). 

Functionalized monoaza-crown ethers are important intermediates for further transformations. The dihydroxyaza-crowns, where the hydroxy groups arc attached to ring carbon atoms, were prepared by reacting a primary amine... 

Epichlorohydrin, when treated with an excess of monoaza-crown, formed the bis(aza-crown) (method D-6) (Belohradsky et al., 1987b). The same bis macrocycle was prepared in a two-step process via an epoxymethyl-substituted aza-crown as shown. Crown-substituted aza-crowns containing an ether linkage were also prepared from the glycidyloxymethyl-substituted crown ethers (see method D-6). 

Extensive tables of the monoaza-crown compounds follow. The tables are organized in order of increasing ring size and complexity of the substituent(s). Where possible, the preparative method is indicated so that one can see how the crown was made. References and yields are given for each compound. 

Bis(methylamino)-3-oxapentane, 41 Bis(monoaza-crown) macrocycles, 181-185 Bis(monoaza-crown) macrocycles, table. 231 Bisparaphenylene-34-crown-8. 75 Bis(peraza-crown) macrocycles, table, 674 Bisbiphenyl-containing peraza-crown-4... 

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