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Gold(I) Complexes Stabilized by Nine- and Ten-Membered N-Heterocyclic Carbene Ligands.

ABSTRACT: 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 tBuOK in the presence of AuCl(SMe₂ ) 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.

SUBMITTER: Cervantes-Reyes A

PROVIDER: S-EPMC6852534 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature

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Gold(I) Complexes Stabilized by Nine- and Ten-Membered N-Heterocyclic Carbene Ligands.

Cervantes-Reyes Alejandro A Rominger Frank F Rudolph Matthias M Hashmi A Stephen K ASK

Chemistry (Weinheim an der Bergstrasse, Germany) 20190808 50

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 tBuOK in the presence of AuCl(SMe<sub>2</sub> ) provided fast access to NHC-gold(I) complexes 3-10. These new NHC-go ...[more]

PMID: 31310385

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