1416083-41-4Relevant academic research and scientific papers
Simple Synthetic Routes to N-Heterocyclic Carbene Gold(I)–Aryl Complexes: Expanded Scope and Reactivity
Cauwenbergh, Thibault,Janssens, Wim,Nahra, Fady,Nolan, Steven P.,Saab, Marina,Tzouras, Nikolaos V.,Van Hecke, Kristof
, p. 5541 - 5551 (2020)
The discovery of sustainable and scalable synthetic protocols leading to gold–aryl compounds bearing N-heterocyclic carbene (NHC) ligands sparked an investigation of their reactivity and potential utility as organometallic synthons. The use of a mild base and green solvents provide access to these compounds, starting from widely available boronic acids and various [Au(NHC)Cl] complexes, with reactions taking place under air, at room temperature and leading to high yields with unprecedented ease. One compound, (N,N′-bis[2,6-(di-isopropyl)phenyl]imidazol-2-ylidene)(4-methoxyphenyl)gold, ([Au(IPr)(4-MeOC6H4)]), was synthesized on a multigram scale and used to gauge the reactivity of this class of compounds towards C?H/N?H bonds and with various acids, revealing simple pathways to gold–based species that possess attractive properties as materials, reagents and/or catalysts.
Continuous Flow Synthesis of [Au(NHC)(Aryl)] (NHC=N-Heterocyclic Carbene) Complexes
Cauwenbergh, Thibault,Tzouras, Nikolaos V.,Scattolin, Thomas,Bhandary, Subhrajyoti,Simoens, Andreas,Van Hecke, Kristof,Stevens, Christian V.,Nolan, Steven P.
supporting information, p. 13342 - 13345 (2021/08/07)
The use of weak and inexpensive bases has recently opened promising perspectives towards the simpler and more sustainable synthesis of Au(I)-aryl complexes with valuable applications in catalysis, medicinal chemistry, and materials science. In recent years, continuous manufacturing has shown to be a reliable partner in establishing sustainable and controlled process scalability. Herein, the first continuous flow synthesis of a range of Au(I)-aryl starting from widely available boronic acids and various [Au(NHC)Cl] (NHC=N-heterocyclic carbene) complexes in unprecedentedly short reaction times and high yields is reported. Successful synthesis of previously non- or poorly accessible complexes exposed fascinating reactivity patterns. Via a gram-scale synthesis, convenient process scalability of the developed protocol was showcased.
Experimental Evaluation of (L)Au Electron-Donor Ability in Cationic Gold Carbene Complexes
Carden, Robert G.,Lam, Nathan,Widenhoefer, Ross A.
supporting information, p. 17992 - 18001 (2017/11/27)
29Si NMR spectroscopy was employed to evaluate the electron donor properties of the (L)Au fragments in the cationic gold (β,β-disilyl)vinylidene complexes [(L)Au=C=CSi(Me)2CH2CH2Si(Me)2]+B(C6F5)4? [L=P(tBu)2o-biphenyl or NHC] relative to the p-substituted aryl group in the α-aryl-(β,β-disilyl)vinyl cations [(p-C6H4X)-C= CSi(Me)2CH2CH2Si(Me)2]+B(C6F5)4?. Similarly, 19F NMR was employed to evaluate the σ- and π-electron donor properties of the (L)Au fragments in the neutral gold fluorophenyl complexes (L)Au(C6H4F) and in the cationic (fluorophenyl)methoxycarbene complexes [(L)AuC(OMe)(C6H4F)]+SbF6? [L=P(tBu)2o-biphenyl or IPr] relative to the p-substituted aryl group of the protonated monofluorobenzophenones [(p-C6H4X)(C6H4F)COH]+OTf?. The results of these studies indicate that relative to p-substituted aryl groups, the gold (L)Au fragments [L=P(tBu)2o-biphenyl or NHC] are significantly more inductively electron donating and are comparable π-donors and for this reason, the extent of (L)Au→C1 electron donation in gold carbene complexes appears to exceed that provided by a p-(dimethyamino)phenyl group. Furthermore, the [L=P(tBu)2o-biphenyl]Au fragment is a nominally stronger electron donor than the (IPr)Au fragment, and both are significantly more inductively electron donating than the (PPh3)Au and [P(OMe)3]Au fragments.
Reactivity of organogold compounds with B(C6F5)3: Gold-boron transmetalation via σ-B/π-Au species
Hansmann, Max M.,Rominger, Frank,Boone, Michael P.,Stephan, Douglas W.,Hashmi, A. Stephen K.
supporting information, p. 4461 - 4470 (2015/04/16)
The reactions of gold-acetylides with B(C6F5)3 afford alkynyl borate species and cationic π-coordinated gold complexes. The analogous reactions with aryl gold species generate gem-diaurated compounds containing a borate counteranion. These new σ-B/π-Au alkynyl borate complexes can be employed as active catalysts in homogeneous catalysis and represent a new silver-free activation pathway. The new alkynyl borate species are fully characterized, and the alkyne fragments are shown to be bound in a σ-B/π-Au fashion. Upon prolonged heating, these compounds undergo a slow C6F5 group transfer to gold affording LAuC6F5 species.
The role of metal hydroxide complexes in late transition metal-mediated transmetalation reaction: The case of gold
Dupuy, Stephanie,Crawford, Luke,Buehl, Michael,Slawin, Alexandra M. Z.,Nolan, Steven P.
supporting information, p. 2380 - 2386 (2012/11/07)
In gold chemistry, the hydroxide function on the metal center was observed to act as a potent transmetalation group facilitator when reacted with boronic acids leading to the exceedingly rapid formation of gold-aryl bonds. Copyright
