Cyclophosphazenic polypodands

Cyclophosphazenic polypodands. Obtained as a mixture from the commercial Brij 30, these cheap and efficient catalysts are comparable to most of the common phase-transfer catalysts. 

In this case, in fact, the nucleophilicity sequence is reversed on switching from the complexes of crown ether 5 to the corresponding cryptates. Interestingly, the same trend of crown ether 5 is found with the corresponding complexes of cyclophosphazenic polypodand 2c. As shown in Table 3. cyclophosphazenic polypodands like 2c have a reactivity only slightly lower (three to four times) than that of the corresponding crown ethers and, hence, can be considered a valid alternative to the more sophisticated cyclic ligands. 

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See also in sourсe #XX -- [ ]

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