Asymmetric Cyclopropanation and Epoxidation via a Catalytically Formed Chiral Auxiliary

For the enantioselective diversification of a single starting material, different chiral catalyst is usually required for each transformation. Herein, we extend concept catalytically formed auxiliary from hydrogenation to asymmetric cyclopropanation and epoxidation tetra-substituted olefins, alleviating need catalysts in alkene functionalization step. The constructed propargylic amines Pd-catalyzed carboetherification step using commercially available trifluoroacetaldehyde hemiacetal tether. installed then controlling stereochemistry standard highly reactive reagents give enantioenriched spirocyclic aminomethylcyclopropanols α-amino-α-hydroxy ketones.