A Neutral PCNHCP Co(I)-Me Pincer Complex as a Universal Catalyst for N-Allylic Isomerization

Earth-abundant metal catalyzed double bond transposition offers a sustainable and atom economical route towards the synthesis of internal alkenes. With emphasis specifically on internal olefins and ethers, the isomerization of allylic amines has been particularly underrepresented in the literature. Herein, we report an efficient methodology for the selective isomerization of N-allylic organic compounds including, amines, amides, and imines. The reaction is catalyzed by a neutral PCNHCP Cobalt(I) pincer complex and proceeds via a π-allyl mechanism that includes an unusual 1,2-methyl migration. The isomerization occurs readily at 80 °C and it is compatible with a wide variety of functional groups. The in-situ formed enamines, could additionally be used for a one-pot inverse-electron-demand Diels-Alder reaction to furnish a series of diversely substituted hetero-biaryls, which is further discussed in this report.