The activity of well-defined N-heterocyclic carbene (NHC)-palladium acetate complexes has been studied in the α-arylation of ketones. The enolate was generated in situ via use of slight excess of sodium tert-butoxide as base. The results showed a high activity, allowing for the coupling of non-activated chlorides. The use of hindered substrates provided an avenue for convenient synthesis of various ketone derivatives. The first examples of α-arylation of ketones at room temperature mediated by an NHC-ligated catalyst are also presented.
Bibliographical noteFunding Information:
The National Science Foundation is gratefully acknowledged for financial support of this work and Umicore AG is gratefully acknowledged for the generous gift of Pd(OAc) 2 . We are also grateful to Boehringer-Ingelheim Pharmaceuticals Inc. for an unrestricted grant.
- N-heterocyclic carbenes