Despite extensive research on transition metal-catalyzed Fujiwara–Moritani type C–H olefinations, the alkenes used in these transformations are still mainly limited to active acrylate esters and styrenes. Selective aryl C–H olefination… Click to show full abstract
Despite extensive research on transition metal-catalyzed Fujiwara–Moritani type C–H olefinations, the alkenes used in these transformations are still mainly limited to active acrylate esters and styrenes. Selective aryl C–H olefination with electron-rich alkenes is recognized as a challenging issue. We herein report that simple and readily accessible electron-deficient [CpRh(III)] and [CpCF3Rh(III)] (CpCF3 = C5Me4CF3) complexes are powerful catalysts for dehydrogenative arylation of electron-rich alkenes, including vinyl acetates, enamides, and vinyl ethers. Employing an electron-withdrawing Cp or CpCF3 ligand instead of the privileged Cp* (C5Me5) ligand not only can facilitate the electrophilic aryl C–H rhodation but also can lower the olefin insertion barrier. Both electron-withdrawing and electron-donating directing groups such as -CONR2 and -NHAc could be employed in these reactions, which provides convenient routes toward a series styryl acetates, N-acetylindoles, and aryl methyl ketones.
               
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