Gold-catalyzed Intermolecular Reaction Research Articles

Unusual selectivity in gold-catalyzed intermolecular Heck reactions

Unusual selectivity in gold-catalyzed intermolecular Heck reactions

Synthesis of α,β-Unsaturated Amidines through Gold-Catalyzed Intermolecular Reaction of Azides with Ynamides.

A concise and flexible synthesis of α,β-unsaturated amidines via gold-catalyzed intermolecular ynamide amination/carbene 1,2-shift between ynamides and benzylic azides has been developed. Under mild reaction conditions, various α,β-unsaturated amidines were obtained in mostly good yields, thus providing an efficient and atom-economic way for the construction of valuable α,β-unsaturated amidines.

Gold-catalyzed intermolecular reaction of ynamides with 3-indolyl azides via an unexpected 1,2-alkyl migration

A gold-catalyzed intermolecular reaction of ynamides with 3-indolyl azides via the presumable α-imino gold carbenes has been developed, providing an alternative and efficient way for the synthesis of valuable 3-amino-β-carbolines in generally good to excellent yields. Importantly, this new protocol involves an unexpected 1,2-alkyl migration pathway.

Gold-Catalyzed Vinyl Ether Hydroalkynylation: An Alternative Pathway for the Gold-Catalyzed Intermolecular Reaction of Alkenes and Alkynes.

In this report, the gold-catalyzed intermolecular reaction of vinyl ethers and terminal alkynes is investigated. Utilizing a triazole gold catalyst lessens gold decomposition in the presence of the vinyl ether and affords an alkynylation product instead of the [2 + 2] product. This protocol has been expanded to include glycal substrates, which undergo a one-pot alkynylation-Ferrier reaction to produce functionalized sugars in moderate to excellent yields with high diastereoselectivity.

ChemInform Abstract: Polysubstituted 2‐Aminopyrrole Synthesis via Gold‐Catalyzed Intermolecular Nitrene Transfer from Vinyl Azide to Ynamide: Reaction Scope and Mechanistic Insights.

A gold-catalyzed intermolecular reaction of vinyl azides and ynamides is described. This process presents an efficient and mild approach to multisubstituted 2-aminopyrroles in good-to-excellent yields. Control experiments were carried out to distinguish the reactivity between vinyl azides and the corresponding 2H-azirines. A plausible reaction mechanism was also proposed according to previous reports and our preliminary mechanistic studies.

Polysubstituted 2-Aminopyrrole Synthesis via Gold-Catalyzed Intermolecular Nitrene Transfer from Vinyl Azide to Ynamide: Reaction Scope and Mechanistic Insights.

A gold-catalyzed intermolecular reaction of vinyl azides and ynamides is described. This process presents an efficient and mild approach to multisubstituted 2-aminopyrroles in good-to-excellent yields. Control experiments were carried out to distinguish the reactivity between vinyl azides and the corresponding 2H-azirines. A plausible reaction mechanism was also proposed according to previous reports and our preliminary mechanistic studies.

Generation of α-Imino Gold Carbenes through Gold-Catalyzed Intermolecular Reaction of Azides with Ynamides.

The generation of α-imino gold carbenes via gold-catalyzed intermolecular reaction of azides and ynamides is disclosed. This new methodology allows for highly regioselective access to valuable 2-aminoindoles and 3-amino-β-carbolines in generally good to excellent yields. A mechanistic rationale for this tandem reaction, especially for the observed high regioselectivity, is supported by DFT calculations.

Gold-catalyzed Synthesis of 4-(2-Oxoalkoxy)butyl Methanesulfonates via Ring-opening of Tetrahydrofuran

Abstract A variety of terminal alkynes were converted into the corresponding 4-(2-oxoalkoxy)butyl methanesulfonates via a gold-catalyzed intermolecular oxidation reaction using 8-ethylquinoline N-oxide as the oxidant and THF as the solvent. This reaction is proposed to proceed through the ring-opening of THF via an α-oxo gold carbene intermediate.

The effect of acceptor-substituted alkynes in gold-catalyzed intermolecular reactions

Abstract Alkynes substituted with electron-withdrawing groups participated in various intermolecular reactions with olefin substrates, including [4 + 2] annulation of propiolic acids, intermolecular metathesis-type reaction and carboalkoxylation involving allylethers.

Gold-catalyzed intermolecular reaction of 2-(1-alkynyl)-2-alken-1-ones with diarylethenes to construct polysubstituted cyclopenta[c]furans through a cascade heterocyclization/[3+2] cycloaddition sequence

A method for preparing polysubstituted cyclopenta[c]furans from 2-(1-alkynyl)-2-alken-1-ones and diarylethenes via gold catalysis is reported. The reaction shows good regioselectivity to afford the desired product in moderate to excellent yields.

ChemInform Abstract: Gold‐Catalyzed Intermolecular Reactions of Propiolic Acids with Alkenes: [4 + 2] Annulation and Enyne Cross Metathesis.

A gold-catalyzed intermolecular reaction of propiolic acids with alkenes led to a [4 + 2] annulation or enyne cross metathesis. The [4 + 2] annulation proceeds with net cis-addition with respect to alkenes and provides an expedient route to α,β-unsaturated δ-lactones, for which preliminary asymmetric reactions were also demonstrated. For 1,2-disubstituted alkenes, unprecedented enyne cross metathesis occurred to give 1,3-dienes in a completely stereospecific fashion. DFT calculations and experiments indicated that the cyclobutene derivatives are not viable intermediates and that the steric interactions during concerted σ-bond rearrangements are responsible for the observed unique stereospecificity.

Synthesis of Allenes via Gold-Catalyzed Intermolecular Reaction of Propargylic Alcohols and Aromatic Compounds

Functionalized allenes are efficiently synthesized in moderate to high yield from gold-catalyzed intermolecular reaction of propargylic alcohols and aromatic compounds. The user-friendly process could be conducted under mild reaction conditions with easily accessible starting materials.

Gold-Catalyzed Intermolecular Reactions of Propiolic Acids with Alkenes: [4 + 2] Annulation and Enyne Cross Metathesis

A gold-catalyzed intermolecular reaction of propiolic acids with alkenes led to a [4 + 2] annulation or enyne cross metathesis. The [4 + 2] annulation proceeds with net cis-addition with respect to alkenes and provides an expedient route to α,β-unsaturated δ-lactones, for which preliminary asymmetric reactions were also demonstrated. For 1,2-disubstituted alkenes, unprecedented enyne cross metathesis occurred to give 1,3-dienes in a completely stereospecific fashion. DFT calculations and experiments indicated that the cyclobutene derivatives are not viable intermediates and that the steric interactions during concerted σ-bond rearrangements are responsible for the observed unique stereospecificity.