N,N,N¢,N¢-(tetrakis-2-pyridylmethyl)ethylenediamine (TPEN) derivatives bearing a polymerizable double bond in the substituent structure of the pyridine ring were synthesized and subjected to copolymerization with N-isopropylacrylamide in the presence of azobisisobutyronitrile. The obtained poly(TPEN-NIPA) gels show thermoresponsive swelling/shrinking behaviors, and are used for the extraction of cadmium(II) (Cd II ) ions from an aqueous solution to examine the relationship between gel characteristics and extraction performance. Polymer gels composed of TPEN derivatives bearing C3, C4, C10 and branched C3 spacer chains were synthesized, and the temperature-dependent Cd ion extraction behaviors of the gels were compared. The gels extracted Cd II ions efficiently from the aqueous solution in a swelling state at 5 1C, whereas little extraction was observed at 45 1C in the shrinking state. Poly(TPEN-NIPA) gel with branched C3 spacers (C3b) shows excellent thermoresponsive extraction performance.
Introduction of polyfluorinated alkyl groups into TPEN (N,N,N′,N′-tetrakis(2-pyridylmethyl)ethylenediamine) derivatives provides soft metal ion extracting agents with high acid tolerance. The TPEN derivative bearing a pentafluoropropoxy substituent efficiently extracts Cd2+ and Am3+ into organic and fluorous solvents.
C-C bond formation O 0282Effect of the Use of Bulky Alkylphosphines in the Sonogashira Coupling with Aqueous Ammonia. -The Sonogashira coupling of terminal alkynes and aryl bromides with aqueous ammonia catalyzed by an in situ formed palladium complex of a bulky alkylphosphine furnishes the coupling product at room temperature. One-pot reaction of Sonogashira coupling followed by intramolecular cyclization with 2-hydroxy-VII) or 2-amino-(IX) aryl bromides leads to a facile synthesis of benzofuran (VIII) and indole (X) derivatives. -(FUKUOKA, S.; NAITO, T.; SEKIGUCHI, H.; SOMETE, T.; MORI*, A.; Heterocycles 76 (2008) 1, 819-826; Dep. Chem. Sci. Eng., Fac. Eng., Kobe Univ., Nada, Kobe 657, Japan; Eng.) -H. Haber
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