A cheap metal catalyzed ring expansion/cross-coupling cascade: a new route to functionalized medium-sized and macrolactones

A Cu or Fe-catalyzed radical ring expansion/coupling cascade was developed. It provides a new access to medium-sized and macrolactones with CN, N 3 , SCN, and X groups. DFT calculations suggest a Cu( i )/Cu( ii )/Cu( iii ) catalytic cycle for the cyanation.