Synthesis and characterization of some transition metal complexes containing a nitrogen-oxygen donor macrocyclic ligand

Summary The synthesis and characterization of some Co^II, Ni^II and Cu^II complexes with a nitrogen-oxygen donor macrocyclic ligand is reported. Analytical data, i.r. and visible spectra are compatible with an octahedral or distorted octahedral coordination around the metal. For each of the CoL(NCS)₂ and NiL(NCS)₂ complexes, two crystalline forms were obtained, having different i.r. absorptions for the thiocyanate groups and different x-ray powder diffraction spectra; the pairs of Co-Ni complexes appear to be isostructural.     

Synthesis of macrocycles containing two pyridine and two polyamine moieties via Pd-catalyzed amination

The synthesis of macrocycles containing two pyridine and two polyamine fragments was carried out by the Pd-catalyzed amination of 2,6-dihalopyridines using polyamines and dioxadiamine. Two alternative approaches were elaborated and compared: via intermediate formation of N^α,N^ω-bis(6-halopyridin-2-yl)polyamines or via 2,6-bis(polyamino)substituted pyridines. The yields of linear and cyclic products were shown to be strongly dependent on the nature of the starting polyamines and that of the halogen atom.     

Synthesis of novel lariat azathia crown macrocycles containing two triazole rings and bis crown macrocycles containing four triazole rings

The 13-hydroxy macrocycles 7a-d were prepared in 40-50% yields by the condensation of 1,ω-bis(4-amino-1,2,4-triazol-3-ylsulfany)alkanes 2a-d with 1,3-bis(2-formyphenoxy)-2-propanol (9). Acylation of 7a-d with 2-chloroacetylchloride gave the corresponding esters 11a,b. Amination of 11a,b with different amines in acetone furnished exclusively the target lariat macrocycles 12a,b and 13 in 60-70% yields. Reaction of 2 equiv. of the macrocycles 11a,b with 1 equiv. of piperazine afforded the novel bis macrocyles 14a,b in 50-60% yields. Reduction of 7a-d with NaBH₄ afforded the corresponding 13-hydroxyazathia crown ethers 15a-d in 65-70% yields.     

Synthesis and chiroptical properties of two new planar-chiral macrocycles

Could simple intraannular-arm macrocyclic systems exist in enantiopure stable forms? The effective synthesis of two representative compounds of such a class, their resolution into enantiomers, and experiments justifying their stability toward racemization are presented.     

Chelating behaviour of new 12-membered Schiff base macrocycles containing pendant groups

Summary The free Schiff base macrocycles 1,4,7,10-tetraazacyclo-dodeca-5,6,11,12-tetraaminoacetic acid-4,6,10,12-tetraene (L¹), 1,4,7,10-tetraazacyclododeca-5,6,11,12-tetraamino-phenyl-4,6,10,12-tetraene (L²) and 1,4,7,10-tetraazacyclo-dodeca-5,6,11,12-tetraaminopyridyl-4,6,10,12-tetraene (L³) have been prepared by the reaction of oxamidediacetic acid, oxamidediphenyl and oxamidedipyridyl, respectively, with ethylenediamine. Their complexes with first row transition metal ions, of types [MLCl₂] and [MLCl₂]Cl, have also been prepared and characterized by physico-chemical and spectroscopic methods. The complexes of divalent metal ions are non-ionic while those of trivalent metal ions appear to be 11 electrolytes. An octahedral geometry is proposed for all the complexes.     

Biological applications of amide and amino acid containing synthetic macrocycles

ABSTRACT

Amino acid derived macrocycles with elaborate well-defined stereochemistry are a unique class of compounds that have been isolated from natural sources. Macrocycles like cyclosporine, octreotide, and valinomycin have been used in multiple applications, like drugs or ion sensors. Chemists have long been fascinated by the unique molecular recognition capabilities of these macrocycles and tried to design synthetic analogs with similar functions. This article is focused on reviewing current research on amide and amino acid containing macrocycles that have been developed in research laboratories for biological recognition, specifically for anion sensing, ion transport, carbohydrate sensing, and peptide sensing.     

Synthesis of a new class of azathia crown macrocycles containing two 1,2,4-triazole or two 1,3,4-thiadiazole rings as subunits

A series of new 1,2/1,3-bis[o-(N-methylidenamino-5-aryl-3-thiol-4H-1,2,4-triazole-4-yl)phenoxy]alkane derivatives 3a-d and bis[o-(N-methylidenamino-2-thiol-1,3,4-thiadiazole-5-yl)phenoxy]alkanes 6a-c were prepared by condensation of 4-amino-5-(aroyl)-4H-1,2,4-triazole-3-thiols 2a-b or 2-amino-5-mercapto-1,3,4-thiadiazole with bis-aldehydes 1a-c. Further reaction of compounds 3a-d and 6a-c with dibromoalkanes afforded the new macrocycles 5a-f and 8a-d. The cyclization does not require high dilution techniques and provides the expected azathia macrocycles in good yields, ranging from 55% to 68%.     

Synthesis of new borazines containing crosslinkable groups

Three new functional group containing borazine derivatives, 2,4,6-tri（allylamino）borazine, 2,4,6-tri（3-ethynylanilino）borazine, and 2,4,6-tri（4-propargyl oxyanilino）borazine were synthesized by aminolysis reaction of 2,4,6-trichloroborazine ClaB3N3H3（TCB）. The new compounds were characterized by infrared （IR） spectra, nuclear magnetic resonance （NMR）, and mass spectrometry （MS）.     

两种四乙酸四氮杂环烷化合物的合成

在氢氧化钾存在下，1，4，7，10-四氮杂环十二烷与溴乙酸进行N-羧甲基化反应，得到N，N′N″N-四乙酸1，4，7，10-四氛杂环十二烷（DOTA，I），经重结晶纯化，产率88．1％．在碳酸钾存在下，1，4，8，11-四氮杂环十四烷与溴乙酸卡酯进行反应，生成N－乙酸苄酯中间体．该中间体在室温和4．04×105Pa氢气压力下，用Pd／C地催化氢解脱苄基得到N，N′N″N-四乙酸1，4，8，11－四氮杂环十四烷（TETA，Ⅲ），产率56．0％。     

Synthesis and antifungal activity evaluation of new heterocycle containing amide derivatives

A series of heterocycle containing amide derivatives (1–28) were synthesised by the combination of acyl chlorides (1a, 2a) and heterocyclic/homocyclic ring containing amines, and their in vitro antifungal activity was evaluated against five plant pathogenic fungi, namely Gibberella zeae, Helminthosporium maydis, Rhizoctonia solani, Botrytis cinerea and Sclerotinia sclerotiorum. Results of antifungal activity analysis indicated that some of the products showed good to excellent antifungal activity, as compound 2 showed excellent activity against G. zeae and R. solani and potent activity against H. maydi, B. cinerea and S. sclerotiorum, and compounds 1, 8 and 10 also displayed excellent antifungal potential against H. maydi, B. cinerea and S. sclerotiorum and good activity against R. solani when compared with the standard carbendazim.     

Synthesis and an X-ray structure of soluble phenylacetylene macrocycles with two opposing bipyridine donor sites

The synthesis of the shape-persistent macrocycles 10a and 10b with two bipyridine units in opposing sides by Hagihara/Sonogashira cross-coupling chemistry of suitably functionalized building blocks is reported. X-ray analysis of single crystals of 10b shows a layered structure with channels filled with solvent molecules and parts of the flexible chains. with which the cycle is decorated for solubility reasons.     

Synthesis, coordination properties, and analytical applications of mixed donor macrocycles containing the 1,10-phenanthroline sub-unit

The coordination properties towards different metal ions of a new class of mixed N/S-, and N/S/O-donor macrocycles containing the 1,10-phenanthroline sub-unit in the cyclic framework are reviewed. The conformational constraints imposed by the heteroaromatic fragment onto the aliphatic portion of the ring determine the coordination mode of these ligands which can stabilise low-valent Ni⁺, Pd⁺, Pt⁺, and Rh⁺ metal complexes. Structural and thermodynamic aspects of the coordination chemistry of these ligands are considered together with possible applications as building blocks in the synthesis of multi-centred systems, and as template in the construction of extended polyiodide networks. However, solution studies demonstrate the inability of these ligands to work as selective and specific fluorescent chemosensors for heavy transition and post-transition metal ions and the formation constants evaluated for the formation of 1:1 complexes with Pb²⁺, Cd²⁺, Hg²⁺, Cu²⁺, and Ag⁺ in acetonitrile are of the same order of magnitude. Nevertheless, some of these macrocyles are extremely effective to recognise Cu²⁺ or Ag⁺ over the other metal ions in transport processes, and have been successfully used as neutral ionophore in the construction of PVC-based ionselective electrodes and supported liquid membranes for analytical detection and separation, respectively, of these metal ions.     

Ferrocene-based anion receptor bearing amide and triazolium donor groups

A novel ferrocene-based anion receptor bearing amide and triazolium donor groups and its anion complexation have been reported. We found that it shows marked electrochemical selectivity to F(-), followed by AcO(-) > Cl(-) > Br(-) > I(-), which is in accordance with (1)H NMR titration results.     

Synthesis of new imines and amines containing organosilicon groups

The Peterson olefination reaction of terephthalaldehyde with tris(trimethylsilyl)methyl lithium, (Me₃Si)₃CLi, in THF at 0 °C gives 4-[2,2-bis(trimethylsilyl)ethenyl]benzaldehyde (1) and 4,4-bis[2,2-bis(trimethylsilyl)ethenyl]benzene (2). The new aldehyde (1) reacts with variety of amines in ethanol to afford the corresponding imines (3) containing vinylbis(trimethylsilyl) group. The newly synthesized imines (3) can be completely converted into amines containing vinylbis(trimethylsilyl) group with an excess amount of NaBH₄. In the case of N-[4-(2,2-bis(trimethylsilyl)ethenyl)benzyl]-2,6-dimethylaniline LiAlH₄ was used as a reducing agent in THF.     

Synthesis of new nucleoside analogs containing amino bisphosphonic groups

Adenosine derivatives containing a 2,2-bis(diethoxyphosphoryl)ethyl or 2,2-diphosphonoethyl group on the amino nitrogen atom were synthesized for the first time by reaction of 5′-chloro-5′-deoxy- and 5′-hydroxy-2′,3′-isopropylideneadenosine with tetraethyl ethene-1,1-diylbis(phosphonate) or tetrakis(trimethylsilyl) ethene-1,1-diylbis(phosphonate).     

Synthesis of macrocycles containing 1,3,4-oxadiazole and pyridine moieties

A series of peptide-like 25–28 membered macrocycles containing 1,3,4-oxadiazoles and pyridines bearing a chiral center scaffold have been synthesized by using known coupling reagents and common protecting groups. The yield of the purified macrocycles was poor on an average, yet it seems to be independent of amino acid substitution or stereochemistry. These macrocycles represent a new class of structures for further development and for future application in high-throughput screening against a variety of biological targets.     

The syntheses of nitrogen‐oxygen donor macrocycles containing pyridine ring

Five new nitrogen‐oxygen mixed donor macrocycles have been prepared by condensation of 2,6‐bis [(2‐formylphenyl)oxymethyl]pyridine with different diamino compounds in hot methanol, followed by a one‐pot reduction of the intermediate bis‐Schiff base. All the macrocycles were identified by elemental analysis, and ir, uv, and nmr spectroscopy.     

π-Electron SCF MO calculations for disubstituted benzene derivatives containing two donor groups

The π-electronic structures and spectra of all possible disubstituted benzene derivatives containing fluoro, chloro, hydroxy, and amino groups have been calculated by the Pariser—Parr—Pople method. For all compounds the same starting parameters determined from the best fits to the spectra of the monosubstituted derivatives were used. The calculations give good results for singlet transition energies as well as for the ground state charge densities and bond orders.     

Novel chiral macrocycles containing two electronically interacting arylene chromophores

Novel chiral macrocycles consisting of two rigid oligoarylene rods and two chiral spiroindane clips have been synthesized by condensation of spiroindane diols and CF3-activated alpha-omega-difluorooligoaryls. Since a broad variety of planar aromatic macrocycles is known, our non-planar, chiral rings represent a new class of macrocyclic compounds. The first two examples, which contain quaterphenylene and diphenylbithiophene rods, are presented in this communication; for one of them a crystal structure is given. The chiroptical properties of the macrocycles can be interpreted as an interplay of the "intra-rod" helicity of individual oligoarylene rods and the "inter-rod" helicity between both chromophores of the macrocycle. The macrocycles can act as chiral dopands of commercially available, and novel, polymeric nematic liquid crystals (emissive polyfluorenes). The "intra-rod" helicity of individual oligoarylene rods is the main feature in determining the resulting helical twisting power (HTP). The cholestric induction in mesogenic, emissive polyfluorenes is of special interest for a realization of electronic devices that have a circularly polarized electroluminescence. The results are also important for an understanding of larger ensembles of chiral rodlike molecules, especially their pi-pi interactions.