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Heteroatom Donor‐Decorated Polymer‐Immobilized Ionic Liquid Stabilized Palladium Nanoparticles: Efficient Catalysts for Room‐Temperature Suzuki‐Miyaura Cross‐Coupling in Aqueous Media
Author(s) -
Doherty Simon,
Knight Julian G.,
Backhouse Tom,
Abood Einas,
Alshaikh Hind,
Clemmet Ashley R.,
Ellison Jack R.,
Bourne Richard A.,
Chamberlain Thomas W.,
Stones Rebecca,
Warren Nicholas J.,
Fairlamb Ian J. S.,
Lovelock Kevin R. J.
Publication year - 2018
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.201800561
Subject(s) - phenylboronic acid , chemistry , ionic liquid , catalysis , palladium , heteroatom , phosphine , aqueous solution , polymer chemistry , polystyrene , coupling reaction , suzuki reaction , polyethylene glycol , nanoparticle , organic chemistry , polymer , chemical engineering , ring (chemistry) , engineering
Palladium nanoparticles stabilized by heteroatom donor‐modified polystyrene‐based polymer immobilized ionic liquids (PdNP@HAD‐PIILP; HAD‐PPh 2 , OMe, NH 2 , CN, pyrrolidone) are highly efficient catalysts for the Suzuki‐Miyaura cross‐coupling in aqueous media under mild conditions. Catalyst modified with phosphine was consistently the most efficient as it gave high yields across a range of substrates under mild conditions at low catalyst loadings. Incorporation of polyethylene glycol into the phosphine modified immobilised ionic liquid support improved catalyst efficacy by improving dispersibility and facilitating access to the active site. Moreover, each of the heteroatom modified catalysts was more active than the corresponding unsubstituted imidazolium‐based polystyrene benchmark as well as commercial samples of Pd/C. Catalyst generated in situ from either [PdCl 4 ]@PPh 2 ‐PIILP or its PEGylated counterpart [PdCl 4 ]@PPh 2 ‐PEGPIILP, by reduction with phenylboronic acid, outperformed their pre‐formed counterparts for the vast majority of substrates examined. The turnover frequency of 16,300 h −1 obtained at room temperature is one of the highest to be reported for palladium nanoparticle‐catalysed Suzuki‐Miyaura cross‐coupling between 4‐bromoacetophenone and phenylboronic acid in aqueous media under such mild conditions.