- Efficient synthesis of a variety of new functionalized oxacalixarenes by Ullmann coupling reactions
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We have developed an efficient method to synthesize a new type of oxacalix[4]arenes containing nitrogen functional groups in a single step, through N,N-dimethylglycine-promoted Ullmann coupling reactions starting from aryl dibromides in yields of up to 37%. With a aryl difluoride as substrate, a large, fully aromatic crown ether 8 could be obtained in 25 % yield. Further functionalization of the nitrogen functional groups in the cores of these oxacalixarenes may offer new opportunities for constructing desirable molecular architectures and a range of nitrogen-based multidentate ligands. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
- Yang, Fei,Yan, Liwei,Ma, Kuoyan,Yang, Li,Li, Jihong,Chen, Lijuan,You, Jinsong
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p. 1109 - 1112
(2007/10/03)
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- Host-Guest Complexation. 53.) Functional Groups Preorganized in Hemispherands for Binding Alkali Metal and Ammonium Cations
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The synthesis and free energies are reported for 10 new hemispherands (1, 2, 4, 6, 7-9, 11-13) binding alkali metal and ammonium picrate salts at 25 deg C in CDCl3 saturated with D2O.These hemispherands possess the general structure I, in which two 4-subs
- Bryant, Judi A.,Helgeson, Roger C.,Knobler, Carolyn B.,deGrandpre, Mark P.,Cram, Donald J.
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p. 4622 - 4634
(2007/10/02)
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