Iridium-catalyzed Enantioselective Intramolecular Cross-dehydrogenative Coupling of Alkyl Aryl Ethers Giving Enantioenriched 2,3-Dihydrobenzofurans

Aryl 2-silyloxyprop-1-yl ethers underwent intramolecular C(sp2)–H/C(sp3)–H cross-dehydrogenative coupling in the presence of Ir/(S)-DTBM-SEGPHOS catalyst. The reaction proceeded enantioselectively to afford 3-methyl-3-silyloxy-2,3-dihydrobenzfurans with up to 99% ee. Aryl 2-silyloxyprop-1-yl ethers underwent intramolecular C(sp2)–H/C(sp3)–H cross-dehydrogenative coupling (CDC) in the presence of Ir/(S)-DTBM-SEGPHOS catalyst. The reaction took place enantioselectively to afford 2,3-dihydrobenzfurans bearing a stereogenic carbon center at the C3 position with up to 99% ee. This C(sp2)–H/C(sp3)–H CDC proceeded through a catalytic tandem process involving dehydrogenation of the alkyl group and enantioselective intramolecular hydroarylation.