Diastereoselective Copper-Mediated Conjugate Addition Of Functionalized Magnesiates For The Preparation Of Bisaryl Nrf2 Activators

A two-step metal-halogen exchange and diastereoselective copper-mediated Michael addition onto a complex alpha,beta-unsaturated system has been developed and applied toward the synthesis of bisaryl Nrf2, activators. Optimization of metal-halogen exchange using (n-Bu)(3)MgLi allowed for the preparation of custom aryl-functionalized magnesiate reagents at noncryogenic temperatures. Following transmetalation, these reagents were used in highly diastereoselective Michael addition reactions.