Recent advances of photoinduced trifluoromethylation and difluoroalkylation under photocatalysis are summarized. Most of photoredox reactions proceed efficiently under mild condition with simple operation. Various fluorinated reagents are developed and applied in different transformations. Usually, the photocatalyst in photocatalytic cycle is initially stimulated to the exited state in the presence of visible light, which then provides an electron to the fluorinated reagent to release CF3 radical or CF2 radical. The subsequent radical addition to unsaturated bond with further transformations would produce the corresponding fluorinated products. Alkenes, alkynes, isocyanides, and arenes are frequently employed as substrates for access to fluorochemicals. The advantages of trifluoromethylation and difluoroalkylation under photocatalysis including mild reaction conditions, good functional group tolerance, and experimental ease will make the approaches attractive for further applications. Organic Chemistry Frontiers Journal Name REVIEW This journal is Journal Name REVIEW This journal is Journal Name REVIEW This journal is Journal Name REVIEW This journal is Journal Name REVIEW This journal is Journal Name REVIEW This journal is Journal Name REVIEW This journal is Journal Name REVIEW This journal is

Cyclization reactions of alkynes, especially the double carbometallation of alkynes, have drawn much interest from organic chemists because of their high efficiency in the construction of polycycles. Utilizing different nucleophiles or catalytic systems, various efficient strategies to access challenging skeletons have been extensively explored in recent years. In this review, achievements in this field are presented in three major parts (the syn-syn, anti-anti, and syn-anti addition reactions of diynes or two alkyne molecules). Cyclization reactions of diynes initiated by nucleophiles, [2+2+n] cycloaddition, or other processes and reactions, involving two identical or different alkynes are described, which provide facile and reliable approaches to various π systems, medium-sized rings, and even macrocycles.

A novel and efficient route for the synthesis of 5H-cyclopenta[c]quinoline derivatives via a palladium-catalyzed domino reaction of o-alkynylhalobenzene with amine is described. The starting materials are easily available, and the reaction proceeds smoothly with high efficiency, which shows broad scope with good functional group tolerance.

A novel and efficient synthesis of 11-fluoro-11H-indenoA C H T U N G T R E N N U N G [1,2-c]quinolines has been developed via a palladium-catalyzed three-component reaction of 2-alkynylbromobenzenes, 2-alkynylanilines, and N-fluorobenzenesulfonimide. The reaction works well with high selectivity. Additionally, the diversity and complexity could be easily introduced via a simple operation from readily available starting materials. In the meantime, a fluorine atom could be incorporated into the scaffold during the reaction process.

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