Palladium-Catalyzed Three-Component Dearomatization/Sulfonylation Cascade.

The diastereoselective synthesis of sulfonylated indolines is reported. A palladium-catalyzed dearomative sulfination of (aza)indole-tethered aryl iodides generates reactive benzylic sulfinates. These intermediates react with electrophiles in a one-pot, two-step process to generate sulfonylated products in good yields and excellent diastereoselectivity. This three-component sequence demonstrates good scalability and can be applied toward the synthesis of sulfonamides. Additionally, further derivatizations of aryl iodide containing products furnish spiro- and alkynylated indoline products.