Photo by morbo from unsplash
We herein report regiodivergent ligand-controlled palladium-catalyzed asymmetric cycloaddition reactions between spirovinylcyclopropyl oxindoles and o-quinone methides. Specifically, by using the chiral P,P-ligand Segphos (L5), we obtained various spirooxindole-3,4-benzo[b]oxepanes in moderate to… Click to show full abstract
We herein report regiodivergent ligand-controlled palladium-catalyzed asymmetric cycloaddition reactions between spirovinylcyclopropyl oxindoles and o-quinone methides. Specifically, by using the chiral P,P-ligand Segphos (L5), we obtained various spirooxindole-3,4-benzo[b]oxepanes in moderate to good yields with excellent enantioselectivities via [4+3] cycloaddition reactions. In contrast, reactions involving Trost's ligand (L7) showed different regio- and stereoselectivities, affording bispirooxindole heterocyclic compounds in good yields via [2+3] cycloaddition reactions.
Journal Title: Organic letters
Year Published: 2022
Link to full text (if available)
Share on Social Media: Sign Up to like & get
recommendations!