Synfacts 2006(1): 0091-0091  
DOI: 10.1055/s-2005-921698
Polymer-Supported Synthesis
© Georg Thieme Verlag Stuttgart · New York

Recyclable Polymer-Supported Pd Catalysts for Aryl Amination Reactions

Contributor(s): Yasuhiro Uozumi, Atsushi Ohtaka
M. Guinó , K. K. (M.) Hii*
Imperial College London, UK
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Publikationsverlauf

Publikationsdatum:
16. Dezember 2005 (online)

Significance

The authors have prepared polymer-supported palladium catalysts from three commercially available phosphine-functionalized polystyrenes, Pd2(dba)3, and P(t-Bu)3. The stability of the catalysts is dependent on the method of preparation and the nature of the polymer-bound phosphine. Thus, substantial catalyst leaching (determined by VT 31P NMR spectroscopy) and/or decomposition (indicated by the deposition of palladium black) were observed for all the catalysts prepared by method A. The catalyst (PS-PCy2)Pd[P(t-Bu)3], prepared by method B, was stable even at 100 ºC, though leaching was observed in the case of catalysts prepared from PS-PPh2 and PS-CH2PPh2. (PS-PCy2)Pd[P(t-Bu)3] prepared by method B can be reused in the amination of chlorotoluene without loss in yield (first run: >95%, second run: >95%).