Nickel-catalyzed Suzuki-Miyaura coupling of a tertiary iodocyclopropane with wide boronic acid substrate scope: Coupling reaction outcome depends on radical species stability

Abstract

We describe a nickel-catalyzed Suzuki-Miyaura arylation of a tertiary iodocyclopropane with arylboronic acids; this is an efficient and convergent strategy for providing various enantioenriched arylcyclopropanes with a quaternary stereogenic center. This is the first metal-catalyzed coupling between a tertiary alkyl electrophile and a wide range of aromatics, including heteroaromatics. We found that the outcome of the Ni-catalyzed coupling with halides as electrophiles was dependent on the stability of the radical species formed during the reaction. The use of tert-butyl alcohol (t-BuOH) as the reaction solvent was very effective, because of its stability under the radical-generating reaction conditions.