Enantioselective Synthesis of 3,3′‐Diaryl‐SPINOLs: Rhodium‐Catalyzed Asymmetric Arylation/BF₃‐Promoted Spirocyclization Sequence

Abstract

The enantioselective synthesis of a series of C₂ -symmetric 3,3'-diarylated 1,1'-spirobiindane-7,7'-diols (3,3'-diaryl-SPINOLs) was developed by sequential Rh-catalyzed twofold asymmetric conjugate arylation/BF₃ -promoted diastereoselective spirocyclization (>20:1 d.r. and >99 % ee for all examples). Some phosphoramidite ligands were prepared from the 3,3'-Ph-SPINOL and applied to several catalytic asymmetric reactions, and the 3,3'-diarylated ligands showed higher enantioselectivities than the privileged nonsubstituted ligands.