A naphthalene-based heterobimetallic triazolylidene Ir^III/Pd^II complex: regioselective to regiospecific C–H activation, tandem catalysis and a copper-free Sonogashira reaction

Abstract

Heterobimetallic complexes featuring mesoionic carbene (MIC) donor ligands are gaining enormous popularity in tandem catalysis owing to the combined action of two different metal centers during catalysis. A rare version...

PdII Triazolylidene Complexes: Ancillary Ligand Dependent Catalytic Applications in Sonogashira Coupling and α‐Arylation Reactions under Copper‐Free Conditions

“…Complex R ‐[ 4 ] also exhibits higher catalytic activity as compared to previously reported complex C (Figure 1). [17] Comparing the catalytic outcomes of complex R ‐[ 4 ] with other Pd II NHC/PPh 3 complexes, it was observed that the catalytic activity of R ‐[ 4 ] is comparable to that of a highly active trinuclear Pd II complex [18b] and in some cases even higher under copper free conditions [6d,e,25c] . The better catalytic outcomes of complex R ‐[ 4 ] over complex R ‐[ 3 ] were correlated with their redox behaviour obtained from electrochemical measurements.…”

Heterobimetallic Complexes of Bi- or Polydentate N-Heterocyclic Carbene Ligands and Their Catalytic Properties

“…The bis-triazolium salt could be deprotonated in a stepwise manner, such that its reaction with [IrCl 2 (Cp*)] 2 in the presence of Cs 2 CO 3 , NaOAc, and KI in acetonitrile led to selective monometalation, yielding the cyclometalated Ir-NHC complex 118 (Scheme 41). The subsequent metalation of the other triazolium fragment of the molecule with PdCl 2 in pyridine in the presence of K 2 CO 3 and KI provided the heterobimetallic (Ir/Pd) bis(triazolylidene) complex 119 [63]. The analogous homobimetallic Pd/Pd complex 120 could be obtained in one step from the bis-triazolium salt.…”

Redox–Transmetalation Reactions: Easy Access to Homo- and Heterodimetallic d8,d10 Complexes

“…Another method involves the use of specific metal moieties as metalloligands to house the second metal center. This approach has afforded two electron mixedvalent {Rh Ι ,Rh ΙΙΙ } 21 and {Ir 0 /Ir ΙΙ } 22 complexes, heterometallic {Ni ΙΙ ,Ru ΙΙ } 16 and {Ir ΙΙΙ ,Pd ΙΙ } 23 cores, as well as the trinuclear {Ni 0 -V-Ni ΙΙ } structure. 24 Other alternatives such as comproportionation, ligand addition, and reductive elimination reactions have also been applied successfully.…”