Ligandstruktur und Komplexierung, XXII. 2,6‐Bis(aminomethyl)pyridin als Komplexligand und neues Kronenethersynthon

Buhleier, E.; Wehner, W.; Vögtle, Fritz

doi:10.1002/jlac.197819780402

Cited by 28 publications

(7 citation statements)

References 9 publications

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“…Synthesis of Macrocycles 9 and 10 (Scheme 2 ) . For the synthesis of macrocycles 9 and 10, the cyclisation was achieved by condensation of an M,CO -di(p-toluenesulfonamide) with 2,6-bis(bromomethyl)pyridine in DMF [46]. 4-Aminobutyric acid or 5-aminovaleric acid were tosylated in 90% yield with TsCl in H,O at 90" in the presence of KOH or NaOH, affording the starting materials 28 and 29.…”

Section: Synthesis Of Polyaza Macrocyclic Ligands Incorporating Pyridmentioning

confidence: 99%

“…[40], and that compound 3 binds two Co cations [44]. Ditopic macrocyclic compounds 9 and 10 form dinuclear Cu complexes [46]. On the other hand, protonated compound 2 like 1 binds ATP4-and ADP3-and catalyses their hydrolysis [50].…”

Section: Synthesis Of Polyaza Macrocyclic Ligands Incorporating Pyridmentioning

confidence: 99%

“…For the macrocyclic polyamines 2-8, the key step, the cyclisation, was achieved by condensation of N,N'-ditosyl-2,6-bis(aminomethyl)pyridine (12) or of TsN(CH,CH,N(Ts)H), with 01,u -dimesyloxy derivatives in hot DMF.Macrocycles 2 and 3 (Scheme 1 ) . Compound 12 was obtained in 94% yield by tosylation with TsCl of 2,6-bis(aminomethyl)pyridine [46] prepared in the three steps from 2,6-bis(hydroxymethyI)pyridine [42]. The reaction of 12 with excess 2-(2-chlorethoxy)ethanol in DMF in the presence of K,CO, gave, in 72% yield, the diol 13 which 2, The macrobicyclic tris(pyridine) analogue of compound 4 has been obtained [41b] by reduction of the corresponding hexaimine [41 a].…”

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Synthesis of Polyaza Macrocyclic Ligands Incorporating Pyridine Units

Hosseini¹,

Comarmond²,

Lehn³

1989

Helvetica Chimica Acta

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The synthesis of nine macrocyclic polyamines 2-10 containing pyridine units is described. These compounds are 22-(9), 24-(24,6,8, lo), or 26-(5.7) membered hexaaza (2,3,9,10) or octaaza (4-7) macrocycles in which one to four pyridine units are incorporated. Compounds 3,4,9, and 10 are homoditopic ligands, whereas 2 and 5 are heteroditopic and 6-8 multitopic receptors. Compounds 2-10 are potential ligands for metal cations as well as, in their protonated forms, for anions. Protonated macrocycles 2-10 are also potential catalysts for the hydrolysis of nucleotides and polyphosphates.

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Section: Synthesis Of Polyaza Macrocyclic Ligands Incorporating Pyridmentioning

confidence: 99%

Section: Synthesis Of Polyaza Macrocyclic Ligands Incorporating Pyridmentioning

confidence: 99%

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confidence: 99%

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Synthesis of Polyaza Macrocyclic Ligands Incorporating Pyridine Units

Hosseini¹,

Comarmond²,

Lehn³

1989

Helvetica Chimica Acta

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“…A successful alternative route to the macrocyclic amine 13 was the formation of a macrocyclic diimine 16 by the reaction of 2,6-~yridinedicarbaldehyde (14) with 3,6-dioxaoctane-l,%diamine (15) under magnesium template conditions in methanol16). This complex then was reduced, without isolation, by NaBH4, and led to the desired diamine 13.…”

Section: Syntheses Of 1 -3mentioning

confidence: 99%

“…Chloroform: Refluxing over KzCO3 and distillation (62 "C). (Merck), 3,6-dioxaoctane-l .B-diamine (15) (Merck), 2,6-diaminopyridine (4) (Janssen), and all other reagents and solvents were used without further purification.…”

Section: Purification Of Soloents and Reagentsmentioning

confidence: 99%

Concave Reagents: Syntheses of Macrobicyclic Pyridines

Lüning

1987

Liebigs Ann. Chem.

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Five new macrobicyclic p y r i h 2a -c and 3a, b were synthesized in yields up to 56% and their basicity was determined in ethanol. pK, values larger than 3 were only found for 3a, b where no electron-withdrawing groups were attached to the pyridine ring. The basicities of3a, b are de$mnined by the whole structure; the larger macrocyclic 3b showed the higher bLqicity.Increased selectivity is a major goal in the development of new reactions, reagents and catalysts2). In biological systems, high selectivities are achieved by enzymes. Reactions with these proteins usually take place at their active sites which often are imbedded in concave parts of the enzyme'). During the last decade, advances in the syntheses of artificial host molecules have been made4). The challenge now is to provide these host molecules with properties found in enzymes (artificial enzymes)".Many standard organic reactions are carried out with acid or base catalysis. A way to improve the selectivities of these reactions may be the combination of catalytic activity with concave topology5'. In the case of bases this would lead to molecules where a basic centre is on the inside of a cavity, comparable to an electric bulb in a lampshade.A change in the selectivity of a pair of base catalyzed reactions should then be expected if the two catalyzed reactions are influenced in different ways by the topology (diameter, depth, shape, etc.) of the saucer-shaped catalyst. Design of a Concave BaseA concave base must contain a basic centre and a structure which allows concavity. In organic molecules basic centres usually are nitrogen atoms. Concavity is present in macrobicyclic molecules. Thus, a macrobicyclic compound must be designed which contains an amine as a base, fixed in such a way that the lone pair of the nitrogen atoms points inwards. Furthermore, the nitrogen atom must be bound in such a way that it cannot invert.Amines suitable for this purpose ar 2,6-disubstituted pyridines. In the pyridine system, the lone pair is located in an sp2 orbital. In contrast to most alkylamines, there is no inversion at the (planar) nitrogen atom. The 2,6-substitution of the pyridine ring holds the pyridine system (and thus the lone pair) in a defined position.The second feature of a concave base is the macrobicyclic system. The two bridgeheads have to connect three bridges each. This can be realized by the use of nitrogen-or CHbridgeheads. But the use of CH units has the disadvantage that with two of these tetrahedral bridgeheads diastereoisomers can be formed (in-in, in-out, out-out)6). In contrast, planar or quickly inverting nitrogen atoms do not lead to diastereoisomers. But the bridgehead-nitrogen atoms must be less basic than the pyridine. Thus, an amine nitrogen (pK, for alkylamine~~): ca. 10) as a bridgehead is forbidden, but an amide nitrogen (pK, for lactams'): ca. 0.5) would be allowed. The amide function can easily be introduced during the macrocyclization step'). Furthermore, amides are quite stable") and, also, the amide function is found in enzymes.I...

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