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Synfacts 2013; 9(1): 0115
DOI: 10.1055/s-0032-1317915
DOI: 10.1055/s-0032-1317915
Polymer-Supported Synthesis
Asymmetric Miyaura–Michael Reaction with Polymeric Rh/Ag Catalysts
Yasukawa T, Miyamura H, Kobayashi S * The University of Tokyo, Japan
Polymer-Incarcerated Chiral Rh/Ag Nanoparticles for Asymmetric 1,4-Addition Reactions of Arylboronic Acids to Enones: Remarkable Effects of Bimetallic Structure on Activity and Metal Leaching.
J. Am. Chem. Soc. 2012;
134: 16963-16966
Polymer-Incarcerated Chiral Rh/Ag Nanoparticles for Asymmetric 1,4-Addition Reactions of Arylboronic Acids to Enones: Remarkable Effects of Bimetallic Structure on Activity and Metal Leaching.
J. Am. Chem. Soc. 2012;
134: 16963-16966
Further Information
Publication History
Publication Date:
17 December 2012 (online)
Significance
Polystyrene-based polymer-incarcerated bimetallic rhodium nanoparticle catalysts PI/CB Rh/Ag 2a–b were prepared from co-polymer 1, carbon black (CB), [Rh(OAc)2]2, and AgSbF6. Asymmetric 1,4-addition of arylboronic acids to enones was carried out with 2 and chiral ligand 3 to give the corresponding ketones in 70–99% yield with 74–98% ee without leaching of rhodium.
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Comment
Catalyst 2a was reused 13 times for the reaction of phenylboronic acid with 2-cyclohexenone. After the 10th use, the recovered catalyst was heated at 170 °C to regain its catalytic activity (1st–8th use: >94% yield, 9th use: 67% yield, 10th use: 60% yield, 11th–14th use: >90% yield, with 98% ee in all cycles).
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