Bis(functionalized NHC) Palladium(II) Complexes via a Postmodification Approach
dataset
posted on 2016-01-26, 12:09 authored by Qiaoqiao Teng, Daniel Upmann, Sheena Ai Zi Ng Wijaya, Han Vinh HuynhA series of 20 bis(functionalized
NHC) Pd(II) complexes have been
conveniently synthesized through postmodification reactions of the
common parent NHC complexes <i>trans</i>-[PdBr<sub>2</sub>(C<sub>3</sub>Br-bimy)<sub>2</sub>] (<b>1a)</b> and <i>trans</i>-[PdBr<sub>2</sub>(C<sub>3</sub>Br-imy)<sub>2</sub>] (<b>1b</b>) (C<sub>3</sub>Br-bimy = 1-benzyl-3-(3-bromopropyl)benzimidazolin-2-ylidene
and C<sub>3</sub>Br-imy = 1-benzyl-3-(3-bromopropyl)imidazolin-2-ylidene)
with an <i>N</i>-C<sub>3</sub>Br tether. Depending on the
nature of the nucleophiles added, competing bromido ligand displacements
also occurred. In comparison to the conventional access to functionalized
NHC complexes, which involves metalation of individually prefunctionalized
azolium salts, this highly modular method proves more effective in
cost and time savings. The tetraalkylammonium-functionalized complex <i>trans</i>-[PdBr<sub>2</sub>(C<sub>3</sub>NEt<sub>3</sub>-bimy)<sub>2</sub>]Br<sub>2</sub> (<b>14</b>) as a product of the second-generation
postmodification of complex <b>1a</b> was also tested for its
catalytic activity in Mizoroki–Heck coupling reactions to study
and model the effect of a catalytic amount of ammonium salt additive
in Pd-catalyzed C–C coupling reactions. The ammonium functionalities
in this complex exhibit a positive effect on the catalysis in comparison
to its parent complexes.
History
Related Materials
- 1. DOI - Is supplement to Bis(functionalized NHC) Palladium(II) Complexes via a Postmodification Approach
