Synthesis of Hexamethyl-1,1′-spirobiindane-Based Chiral Spiro Cp Ligands and Their Application in Rhodium-Catalyzed Enantioselective Aryl C-H Addition to Nitroalkenes

Spirocyclopentadienyl rhodium (SCpRh) complexes are powerful catalystsfor promoting asymmetric C-H functionalization reactions. However,the application of chiral SCp ligands is limited due to tedious syntheticprocedures and expensive starting materials. Herein, we have developeda series of chiral spiro ligands (BCSCp) with 6-7 steps fromcommercially available and cheap Bisphenol C. Their correspondingrhodium complexes have been prepared and successfully applied in enantioselectivearyl C-H addition to nitroalkenes, affording a series of C-Hadducts in up to 88% yield with up to 98% ee.

Automated summary

Researchers have developed a series of chiral spiro ligands (BCSCp) from commercially available and cheap Bisphenol C, and prepared their corresponding rhodium complexes. These complexes have been successfully applied in enantioselective aryl C-H addition to nitroalkenes, producing C-H adducts with yields up to 88% and ee up to 98%.