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Abstract A Rh(I)‐catalyzed C6‐selective C−H arylation of 2‐pyridones with inexpensive, readily available, safe and structurally diverse aryl carboxylic acids with the aid of a pyridine directing group is developed. This decarbonylative arylation protocol features an easy‐to‐handle catalytic system, and is amenable to diversely substituted 2‐pyridones and aryl carboxylic acids. It allows access to a wide range of C6‐arylated 2‐pyridones, including those that are difficult to prepare using conventional C−H arylation processes. The method tolerates various electron‐neutral, electron‐rich and electron‐deficient functional groups, and affords the products in 41–91% yields. magnified image
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Metal‐Free Arylation of Benzothiophenes at C4 by Activation as their Benzothiophene S ‐Oxides
Abstract Benzothiophenes, activated by oxidation to the correspondingS‐oxides, undergo C−H/C−H‐type coupling with phenols to give C4 arylation products. While an electron‐withdrawing group at C3 of the benzothiophene is important, the process operates without a directing group and a metal catalyst, thus rendering it compatible with sensitive functionalities—e.g. halides and formyl groups. Quantum chemical calculations suggest a formal stepwise mechanism involving heterolytic cleavage of an aryloxysulfur species to give a π‐complex of the corresponding benzothiophene and a phenoxonium cation. Subsequent addition of the phenoxonium cation to the C4 position of the benzothiophene is favored over the addition to C3; Fukui functions predict that the major regioisomer is formed at the more electron‐rich position between C3 and C4. Varied selective manipulation of the benzothiophene products showcase the synthetic utility of the metal‐free arylation process.
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- Award ID(s):
- 1955876
- PAR ID:
- 10419103
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- Volume:
- 62
- Issue:
- 29
- ISSN:
- 1433-7851
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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