On the Accessible Reaction Channels of Vinyl Gold(I) Species: π‐ and σ‐Pathways

Abstract

The potential of vinyl Au species to react either through a controlled π- or σ-pathway is demonstrated. This nomenclature is directly derived from the orbitals of the vinyl Au species leading to the newly formed bonds. When the π-bond of the vinyl Au intermediate is transformed into a σ-bond, we name it π-pathway, and a σ- to σ- transformation is named σ-pathway. Examples of reactions following these pathways are a Au-catalysed [3,3]-sigmatropic rearrangement and a protodeauration reaction. These reactions have been studied using intrinsic bond orbitals (IBOs) and allow for the clear identification of these pathways. Energies for the reaction path of the Au-catalysed [3,3]-sigmatropic rearrangement were in addition computed using CCSD(T)-F12. Analysis of the intrinsic reaction coordinate (IRC) of the [3,3]-sigmatropic rearrangement using IBOs further allows us to refine the previous mechanistic proposal and identifies a hidden intermediate along the reaction path.

Hydrogen-Bonding-Assisted Brønsted Acid and Gold Catalysis: Access to Both (E)- and (Z)-1,2-Haloalkenes via Hydrochlorination of Haloalkynes

“…Subsequent protodeauration of C by (AcOH) n would therefore afford the anti -product. 27 This is consistent with our deuterium-labeling experiment: using d 4 -AcOH as the solvent, the deuterated product was obtained in 92% yield ( eq 1 ). This result indicates that AcOH is the proton source; hence, this method could be used to synthesize other deuterium labeled haloalkenes.…”

Simple Synthetic Routes to N‐Heterocyclic Carbene Gold(I)–Aryl Complexes: Expanded Scope and Reactivity

“…Intrigued by the fact that 2 b can be produced sustainably on a multigram scale, we probed its reactivity. When 2 b was dissolved in acetonitrile and HBF 4 ⋅Et 2 O was added, the cationic gold 8 was rapidly formed (Scheme ) . This catalytically active complex is also a valuable precursor to the [{Au(IPr)} 2 ( μ ‐OH)][BF 4 ] catalyst .…”

cPCET versus HAT: A Direct Theoretical Method for Distinguishing X–H Bond‐Activation Mechanisms

“…Thus far, this procedure would require a step by step analysis of every individual point of the IRC and then would require us to estimate by how much a given IBO has changed. In previous studies of closed‐shell reactions, including C(sp 3 )−H activation processes, we have simplified the process of identifying the IBOs which undergo changes by computing the root‐mean‐square deviation of every IBO from the initial partial charge distribution along the intrinsic reaction coordinate. A plot of these values (orbital change, plotted in units of e − ) gives immediate insight into which IBOs are participating in bond making and bond breaking along the reaction path.…”