Synthesis, Structure, and Reactivity of Gold(I) α-Oxo Carbenoid Complexes

Reply to Correspondence on "Unlocking the Chain-Walking Process in Gold Catalysis"

We recently reported the gold-catalyzed Heck and chain-walking reactions, which utilize migratory insertion, β-hydride elimination steps in a catalytic fashion. Budzelaar et al. in their correspondence state that these reactions proceed through gold-catalyzed alkene heteroarylation followed by acid-mediated elimination and cyclization sequence. In response to this correspondence, we have conducted some experiments which convinced us that the product formation solely can not be rationalized based on hetero-arylation of alkenes under ligand-enabled Au(I)/Au(III) catalysis.

Gold(I)-N-Heterocyclic Carbene Synthons in Organometallic Synthesis

The prominent role of gold-N-heterocyclic carbene (NHC) complexes in numerous research areas such as homogeneous (photo)catalysis, medicinal chemistry and materials science has prompted organometallic chemists to design gold-based synthons that permit access to target complexes through simple synthetic steps under mild conditions. In this review, the main gold-NHC synthons employed in organometallic synthesis are discussed. Mechanistic aspects involved in their synthesis and reactivity as well as applications of gold-NHC synthons as efficient pre-catalysts, antitumor agents and/or photo-emissive materials are presented.

Gold(I)-Catalyzed Synthesis of Highly Substituted 1,4-Dicarbonyl Derivatives via Sulfonium [3,3]-Sigmatropic Rearrangement

An efficient and straightforward gold-catalyzed protocol for the synthesis of 2-substituted 4-oxo-4-arylbutanal derivatives from commercially available or easily accessible alkynes and vinylsulfoxide substrates has been developed. Extension of the methodology to the use of 1-cycloalkenyl sulfoxides allowed the facile synthesis of five-, six-, and seven-membered-ring cycloalkyl-1-one backbone. Subsequently, the tetrahydrocycloalkyl[b]pyrrole derivatives, which are found in many active pharmaceutical ingredients, were isolated in good yields. Mechanistic investigation highlighted a [3,3]-sigmatropic rearrangement of a sulfonium intermediate in this process.