Fen Zhao

A tandem arylation/cyclization of 2,3‐allenoic acids with aryl diazonium salts has been achieved under visible light irradiation via a dual photoredox/gold catalytic system. This transformation provides diverse arylated butenolides in moderate to excellent yields (up to 93%) under mild conditions. The reaction tolerates diverse functional groups on both coupling partners. Mechanistic studies support a non‐chain radical pathway involving aryl radical generation. A gram‐scale reaction demonstrates the synthetic utility. This protocol provides an efficient and mild access to functionalized butenolides via dual catalysis.

A novel photosensitizer-free, gold-catalyzed tandem cyclization of 2,3-allenamides with aryl diazonium salts under visible light. Solvent-controlled selectivity gives furanimines or furanones.

A method for the gold-catalyzed spirocyclization of activated alkynes with organoiodides through ligand-enabled gold redox catalysis is described. The reaction proceeds smoothly without the need for an external oxidant.

Alkynyl-containing molecules hold significant importance in organic synthesis, drug discovery, and materials science. Herein, we report an efficient protocol for the C(sp)-C(sp³) cross-coupling of bromoalkynes with primary, secondary, and tertiary alkylboronic acids. Mechanistic experiments suggest that silver and base enable the generation of an alkyl radical intermediate from the alkylboronic acid and then undergo a cascade of α-addition and β-elimination with alkynyl bromides, leading to the construction of C(sp)-C(sp³) bonds. This strategy features readily available starting materials, diverse substrates, and mild and easily handled reaction conditions.

An operationally simple and mild protocol for the visible‐light‐induced intermolecular coupling of silacarboxylic acids with sulfonyl alkynes to form alkynylsilanes is presented. This study highlights the use of inexpensive and readily available 4CzIPN as a photocatalyst, along with more stable silacarboxylic acids as silyl radical precursors, enabling the synthesis of a variety of alkynylsilanes in good to excellent yields, notably without the need for transition metals. The transformation offers several key advantages, including a broad substrate scope, good functional group tolerance, and compatibility with heterocyclic substrates. Furthermore, both the scale‐up reaction and the late‐stage functionalization of natural products have been successfully achieved under mild conditions. These features make the process not only efficient but also versatile and suitable for a wide range of applications in chemical synthesis and modification.

Thioethers and their derivatives play important roles in synthetic chemistry, medicinal chemistry, and materials science. Herein, we report a hemilabile P,N-ligand-assisted gold-catalyzed C-S cross-coupling reaction of organoiodides with disulfides. In this reaction, alkyl or aryl disulfides react smoothly with aryl or vinyl iodides to afford a series of aryl sulfide and vinyl sulfide derivatives in good to excellent yields. The robust synthetic capabilities of thioether synthesis are exemplified by the readily available and easily handled reagents as well as the excellent compatibility with a wide range of functional groups.

Coumarin skeletons are significant structural units frequently used in the fields of synthetic chemistry, medicinal chemistry, and materials science. Herein, we report a hemilabile P,N-ligand-assisted gold-catalyzed difunctionalization of activated alkynes with organohalides. The reaction occurs effectively under mild conditions without requiring an external oxidant, producing a variety of 3-arylated and alkenylated coumarin derivatives in high to excellent yields. This method demonstrates a wide substrate tolerance and superb functional group compatibility and is also suitable for heteroaromatic substrates. Further mechanistic investigations strongly support the proposed mechanism of the reaction.

A gold-catalyzed sulfonylation of aryl/vinyl iodides to synthesize aryl sulfones facilitated by the ligand-enabled Au(I)/Au(III) redox catalysis was developed. In the reaction, aryl sodium sulfinates or sulphinic acids can react smoothly with aryl/vinyl iodides to directly construct various aryl sulfones. The strong synthetic capabilities of sulfone synthesis are demonstrated by its easily available and handled reagents, good functional group compatibility, and late-stage application of complicated biomolecules. Mechanistic studies suggest that the silver salt plays a crucial role in the transmetalation with the Au(I)/Au(III) intermediate, and the gold complex favors Au-S bond formation over Au-O bond formation.

A hemilabile P,N-ligand-assisted gold-catalyzed Hiyama cross coupling reaction of aryl and alkenyl iodides with allylsilanes is described, providing access to a series of allylarenes and 1,4-diene derivatives in good to excellent yields.

A method for the tandem cyclization/alkynylation of allenoates with iodoalkynes via gold catalysis under light irradiation is described. Mechanistic studies support that an energy-transfer event takes place, rather than a redox pathway.