Unexpected reactivity of two-coordinate palladium carbene complexes; synthetic and catalytic implications

Ligand exchange reactions reveal unexpected lability of the carbene ligands in two coordinate palladium(0) N-heterocyclic carbene complexes; the latter are found to be very effective catalysts for amination of aryl chlorides

An improved synthesis of bis(1, 3-di-N-tert-buylimidazol-2-ylidene)palladium(0) and its use in C-C and C-N coupling reactions

A new, improved synthesis of [Pd{CN(tBu)(CH)2N(tBu)}2] (1) and its use as a catalyst in coupling reactions, including aminations, is presented. An interesting side product formed in the synthesis of 1, [Pd(¿3-C4H7){(CN(tBu)(CH) 2N(tBu)}Cl] (2), is also discussed. © 2001 Elsevier Science B.V

The first example of simple oxidative addition of an aryl chloride to a discrete palladium (n-heterocyclic carbene) amination precatalyst

The oxidative addition of an aryl chloride to a discrete palladium n-heteocyclic carbene amination precatalyst, was discussed. It was found that the oxidative addition of 4-chlorotoluene to Pd(0) resulted in the formation of not a four-coordinate complex but rather the arylated imidazolium salt. The identity of imidazolium salt was confirmed by x-ray crystallography

Zirconium and titanium amido complexes with 3,3-dimethyl-1,5-diaza-8-oxacyclodecane; facile C-H activation of the macrocyclic rim

Reaction of the dilithium salt of 3,3-dimethyl-1,5-diaza-8- oxacyclodecane, [(NLi)(2)O], with Zr(NEt)(2)Cl-2(thf)(2) gave the formally 20e(-) complex [Zr(N2O)(2)]; metallation of the macrocycle [(NH)(2)O], with Ti(benzyl)(4) gave rise to [(N2O)* Ti(benzyl)](2) in which the trianionic diamido (N2O)* was formed by an unprecedented C-H activation of the carbon a to the amido nitrogen

Studies on high-temperature amination reactions of aromatic chlorides using discrete Palladium-N-Heterocyclic Carbene (NHC) complexes and in situ palladium/imidazolium salt protocols

The palladium catalysed coupling of aryl chlorides and amines can be readily achieved with short reaction times when carried out at high temperatures under thermal or microwave conditions. These coupling protocols are successful using two co-ordinate palladium-N-heterocyclic carbene complexes, or imidazolium salt protocol