Synthesis and Exploration of Electronically Modified (R)-5,5-Dimethyl-(p-CF3)3-i-PrPHOX in Palladium-Catalyzed Enantio- and Diastereoselective Allylic Alkylation: A Practical Alternative to (R)-(p-CF3)3-t-BuPHOX.

The synthesis of the novel electronically modified phosphinooxazoline (PHOX) ligand, (R)-5,5-dimethyl-(p-CF3)3-i-PrPHOX, is described. The utility of this PHOX ligand is explored in both enantio- and diastereoselective palladium-catalyzed allylic alkylations. These investigations prove (R)-5,5-dimethyl-(p-CF3)3-i-PrPHOX to be an effective and cost-efficient alternative to electronically modified PHOX ligands derived from the prohibitively expensive (R)-t-leucine.