“…Over the past two decades ago, Brookhart [1,2] and Gibson [3,4,5] independently discovered the well-defined bis(imino)pyridine-cobalt and -iron complexes ( A ) as highly active precatalysts for ethylene oligo-/polymerization. In the intervening years, large numbers of different skeletal modifications, such as changes to the N -aryl groups and the backbone of pyridine, have been made to the bis(imino)pyridine scaffolds ( A , Chart 1) [6,7,8,9,10,11,12,13,14,15], culminating in improvements to both catalytic activity and thermal stability [6,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33]. The related progress was collected in several reviews [6,9,10,11,14,15].…”