NHC–AuCl/Selectfluor: A Highly Efficient Catalytic System for Carbene-Transfer Reactions

The combination of NHC–gold complex and Selectfluor has been found to be a highly efficient catalyst system for carbene-transfer reactions, with a turnover number (TON) up to 990000 and a turnover frequency (TOF) up to 82500 h^–1

Gold-Catalyzed Enynal and Enynol Coupling by Selectively Steering Two Transient Vinyl-Gold Intermediates

The vinyl–gold bond is easily accessible but less exploited in homogeneous gold catalysis, which possesses weak nucleophilicity and would be likely to undergo protodemetalation. Herein, a gold-catalyzed enynal and enynol coupling by selectively steering two transient vinyl-gold intermediates is realized under mild conditions. It exhibits high atom economy and good tolerance of functional groups with the added benefit of operational simplicity. The control experiments indicated that the in situ formed vinyl–gold accounts for the reactivity

Silver-Catalyzed Reaction of Enynals with Alkenes: A Tandem 1,3‑Dipolar Cycloaddition/Cyclopropanation

A silver-catalyzed reaction of enynals with alkenes to synthesize a series of polycyclic compounds has been developed. The reaction occurred smoothly using enynals with electron-deficient alkynes or terminal alkynes as substrates. The reaction was proposed to proceed through a tandem 1,3-dipolar cycloaddition/cyclopropanation process. The preliminary investigations of the asymmetric catalytic version revealed that the biphosphine ligand could be used as the potential efficient chiral ligand

CuCl/Et₃N‑Catalyzed Synthesis of Indanone-Fused 2‑Methylene Pyrrolidines from Enynals and Propargylamines

An efficient CuCl/Et₃N-catalyzed tandem reaction for the synthesis of indanone-fused pyrrolidine was developed. In this process, two rings and four bonds are generated in one pot with high atom-economy and step-efficiency. The addition of Et₃N was found as the key factor for the success of the tandem reaction

Iron-catalyzed Benzannulation Reactions of 2‑Alkylbenzaldehydes and Alkynes Leading to Naphthalene Derivatives

An efficient and practical method for the synthesis of naphthalene derivatives via Fe(III)-catalyzed benzannulation of 2-(2-oxoethyl)-benzaldehydes and alkynes has been developed. The system holds the advantages of cheap catalysts, wide substrate scope, and mild reaction conditions

Styrene as 4π-Component in Zn(II)-Catalyzed Intermolecular Diels–Alder/Ene Tandem Reaction

A mild Zn-catalyzed intermolecular Diels–Alder/ene tandem reaction with styrene as a 4π-component is reported. A variety of dihydro­naphthalene products could be prepared in moderate to good yields. Moreover, a combination of DFT calculations and experiments was performed to further understand the mechanism of this unique tandem reaction

A Route to Polysubstituted Aziridines from Carbenes and Imines through a Nondiazo Approach

An efficient method for the synthesis of polysubstituted aziridines utilizing enynones and imines is described. This transformation is achieved through the reaction of imines with donor/donor carbene intermediates, which were generated in situ from the cyclization of enynones. Furthermore, the resulted aziridines were good 1,3-dipoles, which could be efficiently trapped by dipolarophiles to give five-membered heterocycles. The obvious advantages of wide substrate scopes, mild reaction conditions, and high atom efficiency make this system highly appealing for construction of polysubstituted aziridines, 2,5-dihydropyroles, and 1,2,4-triazolidines

CuCl/Et₃N‑Catalyzed Synthesis of Indanone-Fused 2‑Methylene Pyrrolidines from Enynals and Propargylamines

An efficient CuCl/Et₃N-catalyzed tandem reaction for the synthesis of indanone-fused pyrrolidine was developed. In this process, two rings and four bonds are generated in one pot with high atom-economy and step-efficiency. The addition of Et₃N was found as the key factor for the success of the tandem reaction

CuCl/Et₃N‑Catalyzed Synthesis of Indanone-Fused 2‑Methylene Pyrrolidines from Enynals and Propargylamines

An efficient CuCl/Et₃N-catalyzed tandem reaction for the synthesis of indanone-fused pyrrolidine was developed. In this process, two rings and four bonds are generated in one pot with high atom-economy and step-efficiency. The addition of Et₃N was found as the key factor for the success of the tandem reaction

CuCl/Et₃N‑Catalyzed Synthesis of Indanone-Fused 2‑Methylene Pyrrolidines from Enynals and Propargylamines

An efficient CuCl/Et₃N-catalyzed tandem reaction for the synthesis of indanone-fused pyrrolidine was developed. In this process, two rings and four bonds are generated in one pot with high atom-economy and step-efficiency. The addition of Et₃N was found as the key factor for the success of the tandem reaction