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1. Cobalt‐Catalyzed Allylic Alkylation at sp ³ ‐Carbon Centers

   https://doi.org/10.1002/chem.202401707  

   Joseph, Ebbin; Tunge, Jon_A (August 2024, Chemistry – A European Journal)

   Abstract The rising demand and financial costs of noble transition metal catalysts have emphasized the need for sustainable catalytic approaches. Over the past few years, base‐metal catalysts have emerged as ideal candidates to replace their noble‐metal counterparts because of their abundance and easiness of handling. Despite the significant advancements achieved with precious transition metals, earth‐abundant cobalt catalysts have emerged as efficient alternatives for allylic substitution reactions. In this review, allylic alkylations at sp³‐carbon centers mediated by cobalt will be discussed, with a special focus on the mechanistic features, scope, and limitations. 

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2. Forging C(sp ³ )–C(sp ³ ) Bonds with Carbon-Centered Radicals in the Synthesis of Complex Molecules

   https://doi.org/10.1021/jacs.8b11790  

   Pitre, Spencer P.; Weires, Nicholas A.; Overman, Larry E. (February 2019, Journal of the American Chemical Society)
3. Programming sp ³ Quantum Defects along Carbon Nanotubes with Halogenated DNA

   https://doi.org/10.1021/jacs.3c14784  

   Wu, Xiaojian; Kim, Mijin; Wang, Lucy J; Veetil, Abhindev Kizhakke; Wang, YuHuang (April 2024, Journal of the American Chemical Society)

   Atomic defect color centers in solid-state systems hold immense potential to advance various quantum technologies. However, the fabrication of high-quality, densely packed defects presents a significant challenge. Herein we introduce a DNA-programmable photochemical approach for creating organic color-center quantum defects on semiconducting single-walled carbon nanotubes (SWCNTs). Key to this precision defect chemistry is the strategic substitution of thymine with halogenated uracil in DNA strands that are orderly wrapped around the nanotube. Photochemical activation of the reactive uracil initiates the formation of sp3 defects along the nanotube as deep exciton traps, with a pronounced photoluminescence shift from the nanotube band gap emission (by 191 meV for (6,5)-SWCNTs). Furthermore, by altering the DNA spacers, we achieve systematic control over the defect placements along the nanotube. This method, bridging advanced molecular chemistry with quantum materials science, marks a crucial step in crafting quantum defects for critical applications in quantum information science, imaging, and sensing. 

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4. Low-Temperature Single Carbon Nanotube Spectroscopy of sp ³ Quantum Defects

   https://doi.org/10.1021/acsnano.7b03022  

   He, Xiaowei; Gifford, Brendan J.; Hartmann, Nicolai F.; Ihly, Rachelle; Ma, Xuedan; Kilina, Svetlana V.; Luo, Yue; Shayan, Kamran; Strauf, Stefan; Blackburn, Jeffrey L.; et al (September 2017, ACS Nano)
5. Cobalt−NHC Catalyzed C(sp ² )−C(sp ³ ) and C(sp ² )−C(sp ² ) Kumada Cross‐Coupling of Aryl Tosylates with Alkyl and Aryl Grignard Reagents

   https://doi.org/10.1002/cctc.202001347  

   Piontek, Aleksandra; Ochędzan‐Siodłak, Wioletta; Bisz, Elwira; Szostak, Michal (November 2020, ChemCatChem)

   Abstract The first cobalt‐catalyzed cross‐coupling of aryl tosylates with alkyl and aryl Grignard reagents is reported. The catalytic system uses CoF₃and NHCs (NHC=N‐heterocyclic carbene) as ancillary ligands. The reaction proceeds via highly selective C−O bond functionalization, leading to the corresponding products in up to 98 % yield. The employment of alkyl Grignard reagents allows to achieve a rare C(sp²)−C(sp³) cross‐coupling of C−O electrophiles, circumventing isomerization and β‐hydride elimination problems. The use of aryl Grignards leads to the formation of biaryls. The C−O cross‐coupling sets the stage for a sequential cross‐coupling by exploiting the orthogonal selectivity of the catalytic system. 

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