Iridium‐Catalyzed C(sp3)−H Addition of Methyl Ethers across Intramolecular Carbon–Carbon Double Bonds Giving 2,3‐Dihydrobenzofurans.

Intramolecular addition of an O‐methyl C(sp3)−H bond across a carbon‐carbon double bond occurs in the iridium‐catalyzed reaction of methyl 2‐(propen‐2‐yl)phenyl ethers. The Ir/(S)‐DTBM‐SEGPHOS catalyst promotes the reaction efficiently in toluene at 110–135 °C to afford 3,3‐dimethyl‐2,3‐dihydrobenzofurans. Enantioselective C(sp3)−H addition is achieved in the reaction of methyl 2‐(1‐siloxyethenyl)phenyl ethers, affording enantioenriched 3‐hydroxy‐2,3‐dihydrobenzofuran derivatives with up to 96% ee. [ABSTRACT FROM AUTHOR]