Palladium complexes of bis(acyclic diaminocarbene) ligands with chiral N-substituents and 8-membered chelate rings

Application of palladium complexes bearing acyclic amino(hydrazido)carbene ligands as catalysts for copper-free Sonogashira cross-coupling

“…In addition, 1 H NMR spectra exhibit two broad peaks from PdAC carbene @N(H)N(H)Y protons in the range of d 8.8-11.0. Addition of 5-21 to 1-4 in all possible combinations is accompanied by a pronounced downfield d 13 C shift of one of the isocyanide quaternary C atom to the range specific for ADC PdAC carbene (d 160-224 ppm) [5,6,[18][19][20][21][22][23][24][25]. The C carbene @NH 13 C signals in 34-35, 40-41, and 46-49 were found to resonate at ca.…”

Synthesis, characterization and X-ray structures of enatiopure-diamine zinc(II) complexes as pre-catalysts for stereoselective production of poly(rac-lactide)

“…The ligands, peeda and pepda, were synthesised in accordance with a previously published procedure [59,60]. Reactions of the ligands with ZnCl 2 in a 1:1 M ratio in absolute EtOH at ambient temperature led to the isolation of (peeda)ZnCl 2 and (pepda)ZnCl 2 as white solids in yields of 84-86% (Scheme 1).…”

“…3,6-dimethyl-1-dioxane-2,5-dione (rac-LA) was purchased from Aldrich and stored in glove box. The ligands, peeda and pepda, were prepared according to the reported methods [59,60].…”

Carbene Complexes Derived from Metal‐Bound Isocyanides: Recent Advances

“…Third, despite the fact that ADC ligands have been explored much less as catalysts compared to NHC derivatives, the previously reported results in this fi eld [24,31,32,34,37,38,40,43,65] clearly indicate a high potential for ADC complexes in catalysis. Taking into account that the generation of M -ADCs via other routes, as distinct from the use of metal -ligated isocyanides, is often associated with experimental diffi culties, it is to be expected that the development of a metalmediated approach to complexes with ADC ligands from isocyanide precursors will play a major role in the further involvement of these compounds in catalysis.…”

“…This is thermally stable under dinitrogen, but undergoes a slow oxidation to form a bis(amidine) complex under air. In a related study [24] , the reaction of cis -dichlorobis( p -trifl uoromethylphenylisocyanide)palladium(II) with N , N ′ -bis[( R ) -1 -phenylethyl] -1,3 -diaminopropane afforded an enantiomerically pure, C1 -symmetric bis(acyclic diaminocarbene)PdCl 2 complex.…”