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Abstract Despite remarkable recent advances in transition-metal-catalyzed C(sp 3 )−C cross-coupling reactions, there remain challenging bond formations. One class of such reactions include the formation of tertiary -C(sp 3 )−C bonds, presumably due to unfavorable steric interactions and competing isomerizations of tertiary alkyl metal intermediates. Reported herein is a Ni-catalyzed migratory 3,3-difluoroallylation of unactivated alkyl bromides at remote tertiary centers. This approach enables the facile construction of otherwise difficult to prepare all-carbon quaternary centers. Key to the success of this transformation is an unusual remote functionalization via chain walking to the most sterically hindered tertiary C(sp 3 ) center of the substrate. Preliminary mechanistic and radical trapping studies with primary alkyl bromides suggest a unique mode of tertiary C-radical generation through chain-walking followed by Ni–C bond homolysis. This strategy is complementary to the existing coupling protocols with tert -alkyl organometallic or -alkyl halide reagents, and it enables the expedient formation of quaternary centers from easily available starting materials. 

Catalysis plays a significant role in most processes of the chemical industry, especially in the emerging areas of sustainable energy and clean environment. A major challenge is the design of catalysts with the desired synergies in terms of activity, selectivity, stability, and cost. New insights into many fundamental questions related to the challenge have sparked a surge of interest in recent years in the area of exploring copper-based alloy catalysts. In this review, the most recent progress in the explorations of copper-alloy catalysts will be highlighted, with a focus on the structural and mechanistic characterizations of the catalysts in different catalytic reactions. The fundamental understanding of the detailed catalytic synergies of the catalysts for the targeted heterogeneous catalytic reactions depends strongly on the utilization of various analytical techniques for the characterization. Significant progress has been made in utilizing advanced techniques, both ex situ and in situ / operando characterizations, demonstrating the abilities to gain atomic/molecular level insights into the morphological, structural, electronic and catalytic properties of copper alloy catalysts, especially the dynamic surface active sites under the reaction conditions or during the catalytic processes. The focus on structural characterization in this review serves as a forum for discussions on structural and mechanistic details, which should provide useful information for identifying challenges and opportunities in future research and development of copper-alloy catalysts. 

Nanoimprinting by thermoplastic forming has attracted significant attention due to its promise of low-cost fabrication of functionalized surfaces and nanostructured devices, and metallic glasses have been identified as a material class ideally suited for nanoimprinting. In particular, their featureless atomic structure suggests that there may not be an intrinsic size limit to the material’s ability to replicate a mould. Here we demonstrate atomic-scale imprinting into a platinum-based metallic glass alloy under ambient conditions using atomic step edges of a strontium titanate single crystal as a mould. The moulded metallic glass replicates the ‘atomic smoothness’ of the strontium titanate, with identical roughness to the one measured on the mould even after multiple usages and with replicas exhibiting an exceptional long-term stability of years. By providing a practical, reusable, and potentially high-throughput approach for atomic imprinting, our findings may open novel applications in surface functionalization through topographical structuring.