Soluble polymer-supported hindered phosphine ligands for palladium-catalyzed aryl amination

Tatyana V. Khamatnurova, Dongmei Zhang, Jakkrit Suriboot, Hassan S. Bazzi, David E. Bergbreiter

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4 Citations (Scopus)

Abstract

Strategies for synthesis of more effective soluble supported ligands for phosphine-ligated Pd(0) cross coupling catalysts have been explored. Reversible addition-fragmentation chain transfer (RAFT) polymerization has been used to prepare alkane-soluble poly(4-alkylstyrene)-bound phosphine ligands. 4-tert-Butylstyrene and 4-dodecylstyrene were copolymerized with ca. 7 mol% of 4-chloromethylstyrene or a 4-diphenylphosphinestyrene monomer using RAFT chemistry to afford poly(tert-butylstyrene-co-4-dodecylstyrene) copolymers. Polymers with chloromethyl groups were allowed to react with the phenolic group of a hindered dicyclohexylbiarylphosphine ligand. This hindered polymer-bound phosphine formed reactive Pd complexes useful in haloarene amine couplings. All aryl halide amination reactions had Pd leaching that was typically <0.1% of the charged Pd with one example having only 0.02% Pd leaching. These Pd complexes of poly(4-alkylstyrene)-bound phosphines were also compared to similar hindered phosphine complexes formed with a polyisobutylene (PIB), whose terminus was also converted into a dicyclohexylbiarylphosphine ligand. Palladium catalysts ligated by these hindered biarylphosphines on poly(4-alkylstyrene) and PIB-bound both were recyclable in the absence of oxygen, had similar activity, and very low Pd leaching. This journal is

Original languageEnglish
Pages (from-to)2378-2383
Number of pages6
JournalCatalysis Science and Technology
Volume5
Issue number4
DOIs
Publication statusPublished - 1 Apr 2015

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ASJC Scopus subject areas

  • Catalysis

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