Hydrogen-Bonding Activation of Gold(I) Chloride Complexes: Enantioselective Synthesis of 3(2<i>H</i>)-Furanones by a Cycloisomerization-Addition Cascade
Pilar Elías‐Rodríguez, Manuel de La Mata Benítez, Javier Iglesias‐Sigüenza, Elena Dı́ez, Rosario Fernández, José M. Lassaletta, David Monge
Abstract
High Resolution Image Download MS PowerPoint Slide Enantioselective synthesis of 3(2 H )-furanones has been achieved using the intermolecular H-bonding activation of gold(I) chloride complexes. A DM-BINAP [( R )-(+)-2,2′-Bis[di(3,5-xylyl)phoshino]-1,1′-binaphthyl] digold(I) dichloride complex in combination with a sulfonyl squaramide (SO 2 Sq) has been identified as the optimal catalytic system. The process involves a 5- endo - dig oxa-cyclization followed by stereocontrolled addition of indoles. Interestingly, the soft L*Au–Cl activation by H-bonding allowed the recovery of both L*Au–Cl and the activator after chromatographic purification.