π-Alkene/alkyne and carbene complexes of gold(I) stabilized by chelating ligands

Navarro, Miquel; Bourissou, Didier

doi:10.1016/bs.adomc.2021.02.001

Cited by 12 publications

(17 citation statements)

References 159 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To support the existence and catalytic relevance of key π-allyl Au(III) complexes II , stoichiometric reactions were performed (Scheme ). First, π-alkene Au(I) complex A , was synthesized, isolated, and fully characterized (NMR, EA) . Its structure was analyzed computationally, showing in-plane coordination of the CC double bond to gold .…”

Section: Resultsmentioning

confidence: 99%

Au(I)/Au(III) Catalytic Allylation Involving π-Allyl Au(III) Complexes

et al. 2022

Self Cite

View full text Add to dashboard Cite

A (MeDalphos)AuCl complex was found to efficiently catalyze the cross-coupling of indoles and allyl acetates/alcohols. The reaction tolerates many functional groups and selectively affords the branched C3-allylated products from both αand γ-substituted allyl substrates. It takes the advantage of the hemilabile character of the P ∧ N ligand. The C(sp 2 )−C(sp 3 ) coupling operates via a Au(I)/ Au(III) redox cycle and involves a dicationic π-allyl Au(III) complex as a key intermediate. In this case, the allyl moiety adopts an asymmetric σ + π-coordination mode, as substantiated by NMR spectroscopy and density functional theory (DFT) calculations.

show abstract

Section: Resultsmentioning

confidence: 99%

Au(I)/Au(III) Catalytic Allylation Involving π-Allyl Au(III) Complexes

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…One equivalent of biphenyl trifluoromethyl diazomethane 2‐Ph was added at −80 °C to the tricoordinate pseudo‐cationic complex (P^P)AuNTf 2 1 [22] in dichloromethane (DCM) (Scheme 1). The diphosphine o ‐carboranyl (DPCb) ligand was used for its unique chelation property, resulting in a bent L 2 Au + fragment with higher π‐backdonation capacity [15d] . With monodentate phosphines such as JohnPhos, no sign of a Au I trifluoromethyl carbene could be observed by NMR spectroscopy even at low temperature.…”

Section: Resultsmentioning

confidence: 99%

Gold(I) α‐Trifluoromethyl Carbenes: Synthesis, Characterization and Reactivity Studies

et al. 2022

Self Cite

View full text Add to dashboard Cite

Aryl trifluoromethyl diazomethanes 2-R (R = Ph, OMe, CF 3 ) are readily decomposed by the (o-carboranyl)diphosphine gold(I) complex 1. The resulting α-CF 3 substituted carbene complexes 3-R have been characterized by multi-nuclear NMR spectroscopy as well as X-ray crystallography (for 3-Ph). The bonding situation was thoroughly assessed by computational means, showing stabilization of the electrophilic carbene center by π-donation from the aryl substituent and backdonation from Au, as enhanced by the chelating P^P ligand. Reactivity studies under stoichiometric and catalytic conditions substantiate typical carbene-type behavior for 3-Ph.

show abstract

“…The advent of gold-catalyzed π-activation has stimulated huge interest for gold π-complexes over the past three decades . Nevertheless, it was not until 2020 that π-allyl Au(III) complexes were isolated and well characterized.…”

Section: Introductionmentioning

confidence: 99%

Nucleophilic Addition to π-Allyl Gold(III) Complexes: Evidence for Direct and Undirect Paths

et al. 2021

Self Cite

View full text Add to dashboard Cite

π-Allyl complexes play a prominent role in organometallic chemistry and have attracted considerable attention, in particular the π-allyl Pd(II) complexes which are key intermediates in the Tsuji–Trost allylic substitution reaction. Despite the huge interest in π-complexes of gold, π-allyl Au(III) complexes were only authenticated very recently. Herein, we report the reactivity of (P,C)-cyclometalated Au(III) π-allyl complexes toward β-diketo enolates. Behind an apparently trivial outcome, i.e. the formation of the corresponding allylation products, meticulous NMR studies combined with DFT calculations revealed a complex and rich mechanistic picture. Nucleophilic attack can occur at the central and terminal positions of the π-allyl as well as the metal itself. All paths are observed and are actually competitive, whereas addition to the terminal positions largely prevails for Pd(II). Auracyclobutanes and π-alkene Au(I) complexes were authenticated spectroscopically and crystallographically, and Au(III) σ-allyl complexes were unambiguously characterized by multinuclear NMR spectroscopy. Nucleophilic additions to the central position of the π-allyl and to gold are reversible. Over time, the auracyclobutanes and the Au(III) σ-allyl complexes evolve into the π-alkene Au(I) complexes and release the C-allylation products. The relevance of auracyclobutanes in gold-mediated cyclopropanation was demonstrated by inducing C–C coupling with iodine. The molecular orbitals of the π-allyl Au(III) complexes were analyzed in-depth, and the reaction profiles for the addition of β-diketo enolates were thoroughly studied by DFT. Special attention was devoted to the regioselectivity of the nucleophilic attack, but C–C coupling to give the allylation products was also considered to give a complete picture of the reaction progress.

show abstract

π-Alkene/alkyne and carbene complexes of gold(I) stabilized by chelating ligands

Cited by 12 publications

References 159 publications

Au(I)/Au(III) Catalytic Allylation Involving π-Allyl Au(III) Complexes

Au(I)/Au(III) Catalytic Allylation Involving π-Allyl Au(III) Complexes

Gold(I) α‐Trifluoromethyl Carbenes: Synthesis, Characterization and Reactivity Studies

Nucleophilic Addition to π-Allyl Gold(III) Complexes: Evidence for Direct and Undirect Paths

Contact Info

Product

Resources

About