Ligand (biochemistry)

Selectivity

Receptor

Organic chemistry

Combinatorial chemistry

Stereochemistry

Catalysis

Medicinal chemistry

Composite material

Chemistry

Materials science

Pyridine

Alkyl

Reversing

Biochemistry

Alkoxy group

Journal of the American Chemical Society

Controlling site selectivity of C–H activation without using a directing group remains a significant challenge. While Pd(II) catalysts modulated by a mutually repulsive pyridine-type ligand have been shown to favor the relatively electron-rich carbon centers of arenes, reversing the selectivity to favor palladation at the relatively electron-deficient positions has not been possible. Herein we report the first catalytic system that effectively performs meta C–H arylation of a variety of alkoxy aromatics including 2,3-dihydrobenzofuran and chromane with exclusive meta site selectivity, thus reversing the conventional site selectivity governed by native electronic effects. The identification of an effective ligand and modified norbornene (NBE-CO2Me), as well as taking advantage of the statistics, are essential for achieving the exclusive meta selectivity.

<i>meta</i> C–H Arylation of Electron-Rich Arenes: Reversing the Conventional Site Selectivity

meta C–H Arylation of Electron-Rich Arenes: Reversing the Conventional Site Selectivity