Palladium(II) Complexes Bearing a Mixed Set of aNHC/Py/PR3/I2 Ligands: Applications in α-Arylation of Amide and Suzuki-Miyaura Coupling Reactions

Synthesis of PdII Triazolylidene Complexes via an Unusual Csp2‐Csp2 Decoupling Reaction: Applications in α‐Arylation of Amide and Suzuki‐Miyaura Coupling Reactions

“…All complexes have been employed in α ‐arylation of amide, which require comparatively strong base to make the enolate. Though several examples of intramolecular α ‐arylation of amide catalyzed by Pd II complexes are well explored, the intermolecular α ‐arylation of amides are comparatively less common and rarely been explored with Pd II NHC complexes until recently [13a,b,15a,18] . Several examples also demonstrated on slightly high demand of the Pd II pre‐catalysts for these catalytic transformations [13b,18] .…”

“…Complex [ 4 ] also successfully catalyzes other bromobenzenes such as 2‐bromomesitylene (78 % yield), 1‐bromo‐2,4,6‐triisopropylbenzene (94 % yield), 1‐bromo‐2,3,5,6‐tetramethyllbenzene (82 % yield) and 1‐bromo‐2‐methylnapthalene (77 % yield) under identical reaction conditions with good to excellent yields. The complex [ 4 ] also appeared as slightly more active in α ‐arylation of oxindole compared to the similar mononuclear complex B (Figure 1) bearing biphenyl derived mixed MIC/PPh 3 donor set ligands [15a] . This obsevation might be due to the presence of iodo atom at biphenyl moiety of the catalyst [ 4 ], which might help for the substrate activation during catalysis.…”

An efficient and straightforward approach for accessing thionoesters via palladium-catalyzed C–N cleavage of thioamides

“…Based on the known palladium chemistry, 106–109 a plausible mechanism for the catalytic reaction was proposed (Scheme 7): (i) oxidative addition takes place at the C–N bond of thioamide 1a to give thio-acylpalladium( ii ) complex II ; (ii) following transmetalation, complex III is produced by the reaction of benzyl alcohol 2a ; and (iii) then, reductive elimination occurs to form thionoester product 3a and regenerates the Pd(0) species I .…”

A naphthalene-based heterobimetallic triazolylidene IrIII/PdII complex: regioselective to regiospecific C–H activation, tandem catalysis and a copper-free Sonogashira reaction

“…The α-arylation of amides demand for a comparatively strong base and higher catalyst loading. [63][64][65][66][67] The intermolecular version of these catalytic transformations, which is comparatively less common, has recently been explored with palladium(II) complexes possessing both classical NHC and MIC donor ligands. 45,[63][64][65][66][67] The α-arylation of 1-methyl-2oxindole and 2-bromotoluene was initially performed with 2.5 mol% catalyst loading of the dinuclear palladium(II) complex [4] and only 24% yield of 1-methyl-3-phenyl-2-oxindole was obtained.…”

“…[63][64][65][66][67] The intermolecular version of these catalytic transformations, which is comparatively less common, has recently been explored with palladium(II) complexes possessing both classical NHC and MIC donor ligands. 45,[63][64][65][66][67] The α-arylation of 1-methyl-2oxindole and 2-bromotoluene was initially performed with 2.5 mol% catalyst loading of the dinuclear palladium(II) complex [4] and only 24% yield of 1-methyl-3-phenyl-2-oxindole was obtained. The yield was improved in the presence of PPh 3 and a good yield (72%) of the aforementioned product was achieved with a 3 mol% loading of complex [4] in the presence of PPh 3 as an additive.…”