Effective modular iminooxazoline (IMOX) ligands for asymmetric catalysis: [Zn(IMOX)]-promoted enantioselective reduction of ketones by catecholborane.

Abstract

Closing the door to nucleophilic attack on one face of the substrate by using a bulky substituent (see schematic formula) was the key to obtaining high enantiomeric excesses in the reduction of methyl ketones by catecholborane with promotion by zinc complexes of new chiral iminooxazoline (IMOX) ligands. The modular nature, simple design, and possibility to produce tailored IMOX ligands could be advantages in designing the next generation of these chiral ligands.