Manipulation of C–C coupling pathways using different annealing procedures†
Abstract
From scanning tunnelling microscopy and density functional theory calculations, we demonstrate that different annealing mechanisms could modulate distinct reaction pathways, where in a stepwise annealing procedure the detached Br atoms may reduce the activation barrier of CH activation resulting in hierarchical cross dehydrogenative coupling, while in a one-step annealing procedure only Ullmann coupling products are observed.