Finally, it was postulated that the ability of 3 to readily afford 2
could be exploited in a one-pot procedure starting from the NHC
salt. When [Au(IPr)Cl] (1) was generated in situ from IPr.HCl and
[Au(SMe2)Cl] [15], then reacted with potassium tert-butoxide
followed by filtration and water addition, 2 was obtained in 95%
isolated yield (over two steps) (Scheme 3). This novel one-pot
reaction is performed under air and affords 2 in excellent purity.
Attempts to extend this new methodology to other NHC ligands
are ongoing