Marko Hapke is the Chair of Catalysis at the Johannes Kepler University in Linz, Austria, and also a group leader at the Leibniz Institute of Catalysis e.V. at the University of Rostock, Germany. His research centers on the development of novel cobalt catalysts for [2+2+2] cycloaddition reactions and the understanding of factors determinating reactivity and selectivity. Gerhard Hilt is Full Professor at the Carl con Ossietzky University in Oldenburg, Germany. His research interests are applications of electron-transfer-activated transition-metal complexes in organic synthesis, quantification of Lewis acidities, organic electrochemistry, and surface-assisted transformations.