Recent developments in stereoselective iridium-catalyzed allylic alkylation methodologies

We report our ongoing studies in the field of iridium-catalyzed allylic alkylation chem. The first regio-, diastereo-, and enantioselective transition-metal-catalyzed allylic alkylation reaction forming vicinal tertiary and all-carbon quaternary stereocenters between prochiral enolates and an aliph.-substituted electrophile is disclosed. Crit. to the success of this new reaction is the identity and ubiquity of the chloride counterion in addn. to the use of proton sponge, the combination of which affords excellent regio- and enantioselectivities along with good yields and diastereoselectivities. Addnl., a no. of transformations were carried out on the alkylation products to demonstrate the value of this method in rapidly accessing highly functionalized, stereochem. rich polycyclic scaffolds. Further exploration of this chem. has continued to expand the scope of these types of transformations with respect to the nucleophile and electrophile. Our recent efforts in this field will be discussed