Surface‐Plasmon‐Enhanced Transmetalation between Copper and Palladium Nanoparticle Catalyst

Abstract

Surface‐plasmon‐mediated phenylacetylide intermediate transfer from the Cu to the Pd surface affords a novel mechanism for transmetalation, enabling wavelength‐tunable cross‐coupling and homo‐coupling reaction pathway control. C−C bond forming Sonogashira coupling and Glaser coupling reactions in O2 atmosphere are efficiently driven by visible light over heterogeneous Cu and Pd nanoparticles as a mixed catalyst without base or other additives. The reaction pathway can be controlled by switching the excitation wavelength. Shorter wavelengths (400–500 nm) give the Glaser homo‐coupling diyne, whereas longer wavelength irradiation (500–940 nm) significantly increases the degree of cross‐coupling Sonogashira coupling products. The ratio of the activated intermediates of alkyne to the iodobenzene is wavelength dependent and this regulates transmetalation. This wavelength‐tunable reaction pathway is a novel way to optimize the product selectivity in important organic syntheses.

Plasmonic Silver‐Nanoparticle‐Catalysed Hydrogen Abstraction from the C(sp3)−H Bond of the Benzylic Cαatom for Cleavage of Alkyl Aryl Ether Bonds

“…[12] Recently, we found LSPR enhanced transmetalation from copper NPs to palladium NPs, enabling control over cross-coupling and homocoupling reaction pathways by tuning light irradiation wavelength. [13] These studies demonstrate that new plasmonic photocatalyst systems can access novel and often greener, reactive channels not achievable by either conventional heating or semiconductor photocatalysis. Using plasmonic catalysts, it is possible to develop entirely new approaches to achieve chemical synthesis.…”

“…The sharp electromagnetic‐field gradient of the illuminated plasmon metal NPs generates an EM intensity gradient force [11] that enhances the adsorption of some light‐polarisable reactants on the catalyst, which has been shown to switch reaction pathways in some instances [12] . Recently, we found LSPR enhanced transmetalation from copper NPs to palladium NPs, enabling control over cross‐coupling and homo‐coupling reaction pathways by tuning light irradiation wavelength [13] . These studies demonstrate that new plasmonic photocatalyst systems can access novel and often greener, reactive channels not achievable by either conventional heating or semiconductor photocatalysis.…”

Plasmonic Silver‐Nanoparticle‐Catalysed Hydrogen Abstraction from the C(sp3)−H Bond of the Benzylic Cαatom for Cleavage of Alkyl Aryl Ether Bonds

“… [12] Recently, we found LSPR enhanced transmetalation from copper NPs to palladium NPs, enabling control over cross‐coupling and homo‐coupling reaction pathways by tuning light irradiation wavelength. [13] These studies demonstrate that new plasmonic photocatalyst systems can access novel and often greener, reactive channels not achievable by either conventional heating or semiconductor photocatalysis. Using plasmonic catalysts, it is possible to develop entirely new approaches to achieve chemical synthesis.…”

Recent Expedition inPd‐CatalyzedSonogashira Coupling and Related Processes†

“…Recently, Zhang and Sarina reported a Sonogashira coupling in oxygen atmosphere driven by visible light over heterogeneous Cu and Pd nanoparticles. [ 30 ] By tuning the visible and near‐infrared light irradiation, the reaction can be switched between Glaser homo‐coupling and Sonogashira cross‐coupling reactions.…”