Halogen Bond Activation in Gold Catalysis

Gold catalysis has, over the past decades, provided innovative organic transformations under mild conditions with high chemoselectivities. It receives steadily growing attention thanks to its wide synthetic applicability. The catalytically active form, [Ln-Au]+, of ligated gold complexes, [Ln-Au-Cl], is formed via halide abstraction. This typically achieved by anion exchange upon addition an appropriate silver salt reaction mixture. Herein, alternative silver-free route for activation presented, making use halogen bonding promote We demonstrate that a catalytic amount strong bond donor efficiently activates both gold(I) and gold(III) catalysts. Following reaction, catalyst activator are easily recovered. Importantly, this not only reduces metal waste in gold-catalyzed process but also enables upscaling, possibly opening new avenues industrial settings. expensive limited resource, recyclability supreme importance. Based on systematic kinetics, NMR spectroscopic, computational investigations, we describe mechanism bond-activated gold(I/III) using cyclopropanation as model reaction. Our discovery paves way development gold-mediated allow recycling precious may thereby become useful large-scale generation complex molecules.