Synergistic Iridium and Lewis Base Catalyzed Stereodivergent Allylic Substitutions

Key words

allylic substitution - synergistic catalysis - iridium catalysis - Lewis bases - arylacetate esters

Significance

Catalytic asymmetric construction of all possible stereoisomers by a simple and unified method is a challenging research subject in synthetic organic chemistry. The authors developed a stereodivergent allylic substitution with arylacetic acid esters and synergistic iridium/­benzotetramisole (BTM) catalysis.

Comment

The reaction proceeded in the presence of ent-[Ir]-1 and (R)-BTM as synergistic catalysts to give the corresponding products bearing two adjacent stereocenters in high yields and with excellent stereoselectivities. The catalyst system permitted the synthesis of all four stereoisomers of the products. Iridium complex [Ir]-2 also showed catalytic performance in the stereodivergent allylic substitutions.