Synthesis and reactivity of zirconium and hafnium complexes incorporating chelating diamido-N-heterocyclic-carbene ligands

The chemistry of heterocyclic carbenes has experienced a rapid development over the last years. In addition to the imidazolin-2-ylidenes, a large number of cyclic diaminocarbenes with different ring sizes have been described. Aside from diaminocarbenes, P-heterocyclic carbenes, and derivatives with only one, or even no heteroatom within the carbene ring are known. New methods for the synthesis of complexes with N-heterocyclic carbene ligands such as the oxidative addition or the metal atom template controlled cyclization of beta-functionalized isocyanides have been developed recently. This review summarizes the new developments regarding the synthesis of N-heterocyclic carbenes and their metal complexes.

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“…[156] Indenyl and fluorenyl substituted imidazolin-2-ylidenes have been described by Danopoulos et al [157a,b] and Cui et al (Scheme 53).…”

Section: Angewandte Chemiementioning

confidence: 99%

Heterocyclic Carbenes: Synthesis and Coordination Chemistry

2008

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“…However, the application of N-heterocyclic carbene (NHC) donor groups to tether a nucleophilic amido ligand to an electrophilic metal in bifunctional catalysis has yet to be fully exploited, 24,25 and even simple coordination chemistry of multidentate amido-NHC ligands is under-explored. Of note, tridentate bis(amido)-NHC [NCN] pincer complexes of zirconium and hafnium have been reported, 26,27 and amido-bis(NHC) [CNC] and amido-NHC [C,N] complexes of some early and late transition metals are also known. [28][29][30][31][32][33][34][35] Most closely related to this work, Douthwaite has described the palladium [CNC] complex A and, during the course of our research, Luo has reported the Pd complexes (B).…”

Section: Introductionmentioning

confidence: 99%

N-heterocyclic carbene tethered amido complexes of palladium and platinum

et al. 2011

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Graphical Contents EntryThe synthesis and structure of chelating amido-NHC and amido-bis(NHC) complexes of Pd and Pt are described, including the first [CNC]Pt complexes and the first Pd arylamido-NHC complex. AbstractWith a view to applications in bifunctional catalysis, a modular cross-coupling strategy has been used to prepare amine bis(imidazolium) salts (3a and 3b) and an amine mono(imidazolium) salt (6) inert Pt analogue 11 was unreactive under the same conditions. Solid-state structures of the complexes 7a, 7b, 9a, 10, 11 and 12 have been determined by single crystal X-ray diffraction.

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“…During the last decade, large amount of research has focused on non-metallocene related complexes such as borrolides [18], phosphinimides [19], and guanidinate type ligands [20] (where the steric and electronic properties of the ligand are similar to cyclopentadienyl) and ligands such as constrained geometry ligands (CGC) [21][22][23][24][25][26][27][28][29], diamides [30][31][32], phenoxyimine (FI) [33,34] amidinates [35,36], and b-diketiminates [37][38][39] which have been successfully used.…”

Section: Introductionmentioning

confidence: 99%