Stirring or milling? First synthesis of Rh(I)-(di-N-heterocyclic carbene) complexes both in solution and in a ball mill

The “weak base route” leading to transition metal–N-heterocyclic carbene complexes

“…Concomitantly to this early communication, Udvardy, Czégeéni & co-workers published a report reporting the mechanochemical synthesis of a small number of methylene bridged dinuclear rhodium(I)-NHC complexes of the type [{RhCl(COD)}2(𝜇-di-NHC)] using K2CO3 as operational base (Scheme 29). 124 Again, as for the case of Cu(I)-complexes, the a 1 Cycle = milling for 2 min at 550 rpm, followed by 2 min resting Scheme 29. Mechanochemical synthesis of [{RhCl(COD)}2(𝜇-di-NHC)] complexes.…”

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.…”

Stepwise synthesis and catalysis in C–S cross-coupling of pyridine-functionalized N-heterocyclic carbene nickel(ii) complexes by mechanochemistry

“…6 As a consequence, mechanochemistry is nowadays becoming an alternative to the green synthesis of NHC ligands and NHC complexes. 7 For example, an original procedure for the synthesis of N , N -diaryl NHC–palladium complexes using a vibratory ball-mill was reported by Beillard et al 8 Adams et al demonstrated the direct mechanosynthesis of [Pd(NHC) 2 Cl 2 ] using a mortar and pestle. 9 Recently, mechanochemistry combined with solid-state dehydrochlorination reactions 10,11 have also been used for the synthesis of N -heterocyclic carbene complexes.…”