Hydrogen bonding-enabled gold catalysis: ligand effects in gold-catalyzed cycloisomerization of 1,6-enynes in hexafluoroisopropanol (HFIP)

Abstract

Hydrogen bonding has recently emerged as a powerful yet underexplored tool to enable gold(I) catalysis. Here, we demonstrate that HFIP can directly activate [Au(L)Cl] complexes through hydrogen bonding, in the cycloisomerization of 1,6-enynes under mild conditions without the need for external activators. The influence of ancillary ligands on the catalytic efficiency was systematically examined, revealing that ligand–HFIP interactions play a key role in the activation process. This study provides new insight into hydrogen-bond-assisted gold catalysis and offers a simple strategy for activator-free transformations.