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1. 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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2. Ni-Electrocatalytic Enantioselective Doubly Decarboxylative C(sp ³ )–C(sp ³ ) Cross Coupling

   https://doi.org/10.1021/jacs.3c03337  

   Gao, Yang; Zhang, Benxiang; He, Jiayan; Baran, Phil S. (May 2023, Journal of the American Chemical Society)
3. Nickel(IV) Intermediates in Aminoquinoline-Directed C(sp ² )–C(sp ³ ) Coupling

   https://doi.org/10.1021/jacs.2c10778  

   Milbauer, Michael W.; Kampf, Jeff W.; Sanford, Melanie S. (November 2022, Journal of the American Chemical Society)
4. Phosphine-Directed sp ³ C–H, C–O, and C–N Borylation

   https://doi.org/10.1021/acs.joc.0c01706  

   Morris, Kelsey C.; Wright, Shawn E.; Meyer, Gillian F.; Clark, Timothy B. (November 2020, The Journal of Organic Chemistry)

   null (Ed.)
5. Iron-catalyzed C(sp ² )–C(sp ³ ) cross-coupling at low catalyst loading

   https://doi.org/10.1039/C8CY02374C  

   Bisz, Elwira; Kardela, Marlena; Piontek, Aleksandra; Szostak, Michal (March 2019, Catalysis Science & Technology)

   The iron-catalyzed C(sp 2 )–C(sp 3 ) cross-coupling provides a highly economical route to exceedingly valuable alkylated arenes that are widespread in medicinal chemistry and materials science. Herein, we report an operationally-simple protocol for the selective C(sp 2 )–C(sp 3 ) iron-catalyzed cross-coupling of aryl chlorides with Grignard reagents at low catalyst loading. A broad range of electronically-varied aryl and heteroaryl chlorides underwent the cross-coupling using challenging alkyl organometallics possessing β-hydrogens with high efficiency up to 2000 TON. A notable feature of the protocol is the use of environmentally-friendly cyclic urea ligands. A series of guidelines to predict cross-coupling reactivity of aryl electrophiles is provided. 

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