Two-step solid-state synthesis of PEPPSI-type compounds

Abstract

The two-step mechanochemical preparation of carbene-pyridine complexes of palladium and platinum is reported. The organometallic products, which represent a class of commercially available catalysts, are rapidly formed in excellent yield proving solvent-free synthesis to be a viable synthetic alternative even in the case of NHC-containing compounds.

Synthesis, spectroscopic characterization and catalytic activity of platinum(II) carbene complexes

“…The NHC ring is situated at a 66°angle to the coordination plane of Pt, whereas the angle for the pyridine ring is 59°. The carbene C-Pt distance is 1.986(8) Å and the Pt-N 3-chloropyridine bond distance is 2.089(7) Å, which is in agreement with previously published data for similar complexes [36,38,50].…”

Suzuki–Miyaura and Hiyama coupling catalyzed by PEPPSI-type complexes with non-bulky NHC ligand

“…In addition, PEPPSI complexes can be easily obtained and are easy to handle in contrast to other Pd-NHC precursors [8][9][10][11][12][13][14][15]. Recently the new preparations of PEPPSI complexes have been reported [16,17].…”

Expedient synthesis of NOxy-Heterocyclic Carbenes (NOHC) ligands and metal complexes using mechanochemistry

“…Since the discovery of 1,2-bis(adamantan-1-yl)imidazol-2-ylidene as a stable, crystalline compound, [ 8 , 9 ] the poor reputation about nucleophilic carbenes as laboratory curiosities changed dramatically and nowadays nucleophilic carbenes are recognized as useful substrates with diverse applications in catalysis (metallic and organic), [10][11][12][13] in material science [14] and biology [ 15 , 16 ]. In recent years, it has been shown that the mechanosynthesis of ligands and corresponding NHC complexes offers a very efficient approach to the target compounds ( Scheme 1 ) [17][18][19][20][21][22][23][24][25][26][27][28][29][30] . Various types of NHC ligands could be prepared or employed, together with a wide range of metals such as Ag, Cu, Au, Pt, Ru, Pd, to prepare a new collection of organometallics.…”