Lianfen Chen

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.

Gold-Catalyzed Ring Expansion of Enyne-Lactone: Generation and Transformation of 2-Oxoninonium

An efficient gold-catalyzed ring-expansion reaction of enyne-lactones to form 2-oxoninonium intermediates is reported. The 2-oxoninonium generated in this work could undergo further 6π electrocyclization and aromatization reaction to produce different aromatic compounds.

Iron/Zinc-Catalyzed Benzannulation Reactions of 2-(2-Oxo-alkyl)benzketones Leading to Naphthalene and Isoquinoline Derivatives

An efficient method for the synthesis of poly-substituted naphthalene derivatives via Fe(III)-catalyzed [4 + 2] cycloaddition of 2-(2-oxo-alkyl)benzketones with alkynes or enols (generated in situ from alkyl aldehydes or alkyl ketones) is described. A variety of poly-substituted naphthalene derivatives could be synthesized in up to 90% yield under mild reaction conditions. Poly-substituted 1,2-dihydronaphthalene derivatives could be obtained instead through Zn(II)-catalyzed cyclization of 2-(2-oxo-alkyl)benzketones with alkenes. Furthermore, the Fe(III)-catalyzed intramolecular version could lead to isoquinoline derivatives in high yields.

Catalytic [1,3] O-to-C Rearrangement: Rapid Access to Bridged Bicyclic Systems

A catalytic [1,3]u2005O-to-C rearrangement from enyne-ethers was developed for the rapid synthesis of diverse bridged bicyclic systems. In this reaction, a vinyl oxonium intermediate, generated inu2005situ from enyne-ether, was the precursor for the [1,3]u2005O-to-C rearrangement. This versatile protocol represents the first example of catalytic [1,3]u2005O-to-C rearrangement based on ring-expansion strategy, enabling efficient access to bridged bicyclic scaffolds.

A silver-catalyzed three-component reaction via stabilized cation: synthesis of polysubstituted tetrahydronaphthols and tetrahydronaphthylamines

An efficient and stereoselective method for the synthesis of polysubstituted tetrahydronaphthols and tetrahydronaphthylamines through a silver-catalyzed three-component reaction of enynals/enynimines, alkenes and H2O via a stabilized cation intermediate has been developed.

Cu(I)-Catalyzed stereoselective synthesis of trisubstituted Z-enol esters via interrupting the 1,3-O-transposition reaction

An efficient Cu(I)-catalyzed stereoselective synthesis of trisubstituted Z-enol esters via interrupting the 1,3-O-transposition process is reported. This method provided a convenient approach to highly functionalized Z-enol esters with mild reaction conditions and wide substrate scope.