Silver-Free Gold-Catalyzed Heterocyclizations through Intermolecular H-Bonding Activation
Pilar Elías‐Rodríguez, Esteban Matador, Manuel de La Mata Benítez, Tomás Tejero, Elena Dı́ez, Rosario Fernández, Pedro Merino, David Monge, José M. Lassaletta
Abstract
High Resolution Image Download MS PowerPoint Slide Modulable monosulfonyl squaramides have been shown to exert activation of gold(I) chloride complexes through H-bonding in an intermolecular way. Combinations of (PPh 3 )AuCl or IPrAuCl complexes and an optimal sulfonyl squaramide cocatalyst bearing two 3,5-bis(trifluoromethyl)phenyl groups efficiently catalyzed diverse heterocyclizations and a cyclopropanation reaction, avoiding in all cases undesired side reactions. Computational studies indicate that the Au–Cl bond breaks by transligation to the triple bond in a ternary complex formed by the actual AuCl···HBD catalyst and the substrate.