Aza-crown ether
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In
- Selected aza-crowns and their complexes
-
coordination chemistry. -
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![Plerixafor, a derivative of cyclam, is used to treat lymphoma and multiple myeloma.[6]](//upload.wikimedia.org/wikipedia/commons/thumb/d/d1/Plerixafor.svg/120px-Plerixafor.svg.png)
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2.2.2-Cryptand is an aza-crown of the mixed ether-amine variety.
![Plerixafor, a derivative of cyclam, is used to treat lymphoma and multiple myeloma.[6]](/File:Plerixafor.svg){kind=small}
Synthesis
The synthesis of aza crown ethers are subject to the challenges associated with the preparation of
macrocyclizations
.
Variants
Many kinds of aza crown ethers exist.
- Variable length linkers
Aza crowns often feature trimethylene ((CH2)3) as well as ethylene ((CH2)2) linkages. One example is cyclam (1,4,8,11-tetraazacyclotetradecane).
- Tertiary amines
In many aza-crown ethers some or all of the amines are tertiary. One example is the tri(
trimethyltriazacyclononane. Cryptands
, three-dimensional aza crowns, feature tertiary amines.
- Mixed ether-amine ligands
Another large class of macrocyclic ligands feature both ether and amines..[8] One example is the diaza-18-crown-6, [(CH2CH2O)2(CH2CH2NH)]2.[9]
- Lariate crowns
The presence of the amine allows the formation of
Lariat crown ethers, which feature sidearms that augment complexation of cation.[10]
References
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- doi:10.1039/b106367g.
- .
- ^ .
- PMID 17324009.
- .
- .
- .
- PMID 12379140.