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1. CuPd Nanoparticles as a Robust Catalyst for Electrochemical Allylic Alkylation

   https://doi.org/10.1002/anie.202006293  

   Yin, Zhouyang ; Pang, Huan ; Guo, Xuefeng ; Lin, Honghong ; Muzzio, Michelle ; Shen, Mengqi ; Wei, Kecheng ; Yu, Chao ; Williard, Paul ; Sun, Shouheng ( June 2020 , Angewandte Chemie International Edition)

   An efficient CuPd nanoparticle (NP) catalyst (3 nm CuPd NPs deposited on carbon support) is designed for catalyzing electrochemical allylic alkylation in water/isopropanol (1:1 v/v) and 0.2 mKHCO₃solution at room temperature. The Pd catalysis was Pd/Cu composition‐dependent, and CuPd NPs with a Pd/Cu ratio close to one are the most efficient catalyst for the selective cross‐coupling of alkyl halides and allylic halides to form C−C hydrocarbons with product yields reaching up to 99 %. This NP‐catalyzed electrochemical allylic alkylation expands the synthetic scope of cross‐coupling reactions and can be further extended to other organic reaction systems for developing green chemistry electrosynthesis methods.

    

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2. CuPd Nanoparticles as a Robust Catalyst for Electrochemical Allylic Alkylation

   https://doi.org/10.1002/ange.202006293  

   Yin, Zhouyang ; Pang, Huan ; Guo, Xuefeng ; Lin, Honghong ; Muzzio, Michelle ; Shen, Mengqi ; Wei, Kecheng ; Yu, Chao ; Williard, Paul ; Sun, Shouheng ( June 2020 , Angewandte Chemie)

   An efficient CuPd nanoparticle (NP) catalyst (3 nm CuPd NPs deposited on carbon support) is designed for catalyzing electrochemical allylic alkylation in water/isopropanol (1:1 v/v) and 0.2 mKHCO₃solution at room temperature. The Pd catalysis was Pd/Cu composition‐dependent, and CuPd NPs with a Pd/Cu ratio close to one are the most efficient catalyst for the selective cross‐coupling of alkyl halides and allylic halides to form C−C hydrocarbons with product yields reaching up to 99 %. This NP‐catalyzed electrochemical allylic alkylation expands the synthetic scope of cross‐coupling reactions and can be further extended to other organic reaction systems for developing green chemistry electrosynthesis methods.

    

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3. Enantiospecific equilibrium adsorption and chemistry of d ‐/ l ‐proline mixtures on chiral and achiral Cu surfaces

   https://doi.org/10.1002/chir.23153  

   Dutta, Soham ; Gellman, Andrew J. ( November 2019 , Chirality)

   A fundamental understanding of the enantiospecific interactions between chiral adsorbates and understanding of their interactions with chiral surfaces is key to unlocking the origins of enantiospecific surface chemistry. Herein, the adsorption and decomposition of the amino acid proline (Pro) have been studied on the achiral Cu(110) and Cu(111) surfaces and on the chiral Cu(643)^R&Ssurfaces. Isotopically labelled 1‐¹³C‐l‐Pro has been used to probe the Pro decomposition mechanism and to allow mass spectrometric discrimination ofd‐Pro and 1‐¹³C‐l‐Pro when adsorbed as mixtures. On the Cu(111) surface, X‐ray photoelectron spectroscopy reveals that Pro adsorbs as an anionic species in the monolayer. On the chiral Cu(643)^R&Ssurface, adsorbed Pro enantiomers decompose with non‐enantiospecific kinetics. However, the decomposition kinetics were found to be different on the terraces versus the kinked steps. Exposure of the chiral Cu(643)^R&Ssurfaces to a racemic gas phase mixture ofd‐Pro and 1‐¹³C‐l‐Pro resulted in the adsorption of a racemic mixture; i.e., adsorption is not enantiospecific. However, exposure to non‐racemic mixtures ofd‐Pro and 1‐¹³C‐l‐Pro resulted in amplification of enantiomeric excess on the surface, indicative of homochiral aggregation of adsorbed Pro. During co‐adsorption, this amplification is observed even at very low coverages, quite distinct from the behavior of other amino acids, which begin to exhibit homochiral aggregation only after reaching monolayer coverages. The equilibrium adsorption ofd‐Pro and 1‐¹³C‐l‐Pro mixtures on achiral Cu(110) did not display any aggregation, consistent with prior scanning tunneling microscopy (STM) observations ofdl‐Pro/Cu(110). This demonstrates convergence between findings from equilibrium adsorption methods and STM experiments and corroborates formation of a 2D random solid solution.

    

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4. A highly site-selective radical sp 3 C–H amination of azaheterocycles

   https://doi.org/10.1039/C8SC00590G  

   Bentley, Keith W. ; Dummit, Krysta A. ; Van Humbeck, Jeffrey F. ( January 2018 , Chemical Science)

   This report describes the development of a novel C–H amination strategy using both a Cu(ii) Lewis acid and an organic hydrogen atom transfer catalyst to activate benzylic C–H bonds adjacent to aromatic N-heterocycles.

    

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5. Electrochemical Reduction of CO 2 : A Common Acetyl Path to Ethylene, Ethanol or Acetate

   https://doi.org/10.1149/1945-7111/ad2cc1  

   Dauda, Monsuru ; Hendershot, John ; Bello, Mustapha ; Park, Junghyun ; Loaiza Orduz, Alvaro ; Lombardo, Nicholas ; Kizilkaya, Orhan ; Sprunger, Phillip ; Engler, Anthony ; Plaisance, Craig ; et al ( March 2024 , Journal of The Electrochemical Society)

   Ethylene is well known as the primary product of CO₂reduction at Cu electrocatalysts using zero-gap membrane electrode assembly cells with gas diffusion cathodes. Other types of Cu electrocatalysts including oxide-derived Cu, CuSn and CuSe yield relatively more C₂oxygenates; however, the mechanisms for C₂product selectivity are not well established. This work considers selectivity trends of Cu-P_0.065, Cu-Sn_0.03, and Cu₂Se electrocatalysts made using a standard one pot synthesis method. Results show that Cu-P_0.065electrocatalysts (Cu^δ+= 0.13) retain ethylene as a primary product with relatively higher Faradaic efficiencies (FE = 43% at 350 mA cm⁻²) than undoped Cu electrocatalysts (FE = 31% at 350 mA cm⁻²) at the same current density. The primary CO₂reduction product at Cu-Sn_0.03(Cu^δ+= 0.27) electrocatalysts shifts to ethanol (FE = 48% at 350 mA cm⁻²) while CO₂reduction at Cu₂Se (Cu^δ+= 0.47) electrocatalysts favor acetate production (FE = 40% at 350 mA cm⁻²). Based on these results, we propose a common acetyl intermediate and a mechanism for selective formation of ethylene, ethanol or acetate based on the degree of partial positive charge (δ⁺) of Cu reaction sites.

    

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