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Abstract Aryl tosylates are an attractive class of electrophiles for cross‐coupling reactions due to ease of synthesis, low price, and the employment of C−O electrophiles, however, the reactivity of aryl tosylates is low. Herein, we report the Ni‐catalyzed C(sp2)−C(sp3) Kumada cross‐coupling of aryl tosylates with primary and secondary alkyl Grignard reagents. The method delivers valuable alkyl arenes by cross‐coupling with challenging alkyl organometallics possessing β‐hydrogens that are prone to β‐hydride elimination and homo‐coupling. The reaction is catalyzed by an air‐ and moisture stable‐Ni(II) precatalyst. A broad range of electronically‐varied aryl tosylates, including bis‐tosylates, underwent this transformation, and many examples are suitable at mild room temperature conditions. The combination of Ar−X cross‐coupling with the facile Ar−OH activation/cross‐coupling strategy permits for orthogonal cross‐coupling with challenging alkyl organometallics. Furthermore, we demonstrate that the method operates with TON reaching 2000, which is one of the highest turnovers observed to date in Ni‐catalyzed cross‐couplings. magnified image
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Selenenate Anions (PhSeO − ) as Organocatalyst: Synthesis of trans ‐Stilbenes and a PPV Derivative
Abstract The selenenate anion (RSeO−) is introduced as an active organocatalyst for the dehydrohalogen coupling of benzyl halides to formtrans‐stilbenes. It is shown that RSeO−is a more reactive catalyst than the previously reported sulfur analogues (sulfenate anion, RSO−) and selenolate anions (RSe−) in the aforementioned reaction. This catalytic system was also applied to the benzylic‐chloromethyl‐coupling polymerization (BCCP) of a bis‐chloromethyl arene to form ppv (poly(p‐phenylene vinylene))‐type polymers with high yields, Mn(average molecular weight) up to 13,000 and Đ (dispersity) of 1.15. magnified image
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- Award ID(s):
- 1902509
- PAR ID:
- 10128118
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Synthesis & Catalysis
- Volume:
- 362
- Issue:
- 3
- ISSN:
- 1615-4150
- Format(s):
- Medium: X Size: p. 659-666
- Size(s):
- p. 659-666
- Sponsoring Org:
- National Science Foundation
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