Functionalisable N‐Heterocyclic Carbene–Triazole Palladium Complexes and Their Application in the Suzuki–Miyaura Reaction

Abstract

Seven functionalised N-heterocyclic carbene (NHC) ligands and their corresponding palladium(II) complexes have been synthesised with a triazole moiety as a modular and stable linkage between the catalytic centre and the secondary functional group. The complexes were prepared in good yields and fully characterised by NMR spectroscopy, mass spec- [a]2088 trometry and X-ray crystallography. The complexes are active in the Suzuki-Miyaura cross-coupling reaction, with catalytic activities maintained whatever the triazolyl substituent. This opens the possibility for various functionalisations of NHC-palladium complexes.

N-heterocyclic carbene gold(i) and silver(i) complexes bearing functional groups for bio-conjugation

“…33,34 Also, NHC ligands featuring a pendant alkyne group can be functionalized via CuAAC prior to metalation. [35][36][37] Considered one of the most useful reactions in bio-conjugation, the azide-alkyne click 38 reaction finds use in a wide range of bioconjugation applications including labeling proteins, immobilizing peptides on a surface, and functionalizing DNA. 20,39 Considering the ample precedent, an alternative NHC-metal conjugation strategy was sought that involves appending an alkyne group to an NHC metal complex.…”

Cross coupling reactions catalyzed by (NHC)Pd(II) complexes

“…107 Functionalizable Nheterocyclic carbene-triazole palladium complex (C74) was active in the Suzuki cross-coupling reaction (Table 8, entries 31 and 32). 108 Sulfonated water-soluble PEPPSI-Pd-NHC-type complexes, C75, bearing one dipp substituent on one N atom of the imidazole ring, displayed good recyclability and performed couplings of aryl chlorides and bromides at room temperature (Table 8, entries 33-36). 109 The cyclometalated complex C76 was shown to catalyze the coupling of 9-bromophenanthrene with a wide scope of aryl boronic acids, irrespective of their electronic properties and at a very low catalyst concentration (Table 8, entries 37-39).…”