NHC ligands versus cyclopentadienyls and phosphines as spectator ligands in organometallic catalysis

Electronic structures of silver oxides

“…Both Ag 2 O and AgO have uses in battery technologies [16][17][18][19] and antibacterial applications. [20][21][22] Ag 2 O is also used in molecular sensor technologies, 23 for example, as an enzymeless glucose sensor with Cu, 23,24 water splitting, 25 optical memories, 26 and organic catalysis, for example, in transmetalation 27 and the oxidation of aldehydes by molecular oxygen. 28 Additionally, Ag 2 O is used as a component of a range of fast-ion conducting glasses of the form AgIAg 2 Ag 2 O has been the most widely studied of the different silver oxides, with investigations mainly focusing on the electronic structure of the material [33][34][35][36] and the interaction and bonding between the silver and oxygen atoms (primarily concerning the degree of covalency).…”

New Heterogenized Gold(I)‐Heterocyclic Carbene Complexes as Reusable Catalysts in Hydrogenation and Cross‐Coupling Reactions

“…[6] The application of N-heterocyclic carbene (NHC) ligands represents one of the most important developments in the field of metal-mediated catalysis over recent years and valuable contributions have been made to a diversity of reactions. [7] Commonly, NHCs have been described as alternatives to tertiary phosphines in terms of bonding and reactivity, [8] but metalcarbene complexes are often more stable than similar metal-phosphine complexes, [9] and NHCs have been used as alternatives to phosphines as ligands in a broad range of transition metal catalysts owing to their special donor properties. [8] As a result, a large variety of metal-NHC complexes are known, many of which have been successfully used in catalytic applications.…”

“…[7] Commonly, NHCs have been described as alternatives to tertiary phosphines in terms of bonding and reactivity, [8] but metalcarbene complexes are often more stable than similar metal-phosphine complexes, [9] and NHCs have been used as alternatives to phosphines as ligands in a broad range of transition metal catalysts owing to their special donor properties. [8] As a result, a large variety of metal-NHC complexes are known, many of which have been successfully used in catalytic applications. [10] Interestingly, most studies focussing on catalysts incorporating NHC ligands have revolved around the platinum metal groups.…”

Synthesis and properties of heteroaromatic carbenes of the imidazole and triazole series and their fused analogues

“…6,7 However, today a large number of compounds have been isolated; these are predominantly heterocyclic species and include heteroaromatic carbenes, phosphanylsilylcarbenes, aminoalkyl-and diamino-carbenes of cyclic and acyclic series, borazino-and borazolo-carbenes, etc. [8][9][10][11][12][13][14][15][16][17][18][19][20] One of the major focuses of carbene applications has been the catalysis of organic reactions. [21][22][23][24][25][26][27][28][29][30] The connection between individual carbene structure and function has been reported in many publications.…”