Premium
Gold(I) Complexes Stabilized by Nine‐ and Ten‐Membered N‐Heterocyclic Carbene Ligands
Author(s) -
CervantesReyes Alejandro,
Rominger Frank,
Rudolph Matthias,
Hashmi A. Stephen K.
Publication year - 2019
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201902458
Subject(s) - carbene , chemistry , stereochemistry , medicinal chemistry , organic chemistry , catalysis
Nine‐ and ten‐membered N‐heterocyclic carbene (NHC) ligands have been developed and for the first time their gold(I) complexes were synthesized. The protonated NHC pro‐ligands 2 a – h were prepared by the reaction of readily available N , N′ ‐diarylformamidines with bis‐electrophilic building blocks, followed by anion exchange. In situ deprotonation of the tetrafluoroborates 2 a – h with t BuOK in the presence of AuCl(SMe 2 ) provided fast access to NHC‐gold(I) complexes 3 – 10 . These new NHC‐gold(I) complexes show very good catalytic activity in a cycloisomerization reaction (0.1 mol % catalyst loading, up to 100 % conversion) and their solid‐state structures reveal high steric hindrance around the metal atom (% V bur up to 53.0) which is caused by their expanded‐ring architecture.