Chun-Yang He

Pd-Catalyzed Oxidative Cross-Coupling of Perfluoroarenes with Aromatic Heterocycles

A straightforward and practical method for direct Pd(OAc)(2)-catalyzed oxidative cross-coupling of electron-deficient perfluoroarenes with aromatic heterocycles has been developed. Because of its low catalyst loading (2.5 mol %), high reaction efficiency, good chemo- and regioselectivity, and excellent functional-group compatibility, this protocol provides a useful and operationally simple access to perfluoroarene-thiophene structures of interest in functional materials for electronic devices.

Pd(OAc)(2) catalyzed olefination of highly electron-deficient perfluoroarenes.

An efficient, Pd(OAc)(2) catalyzed method for direct olefination of highly electron-deficient perfluoroarenes was developed. The reaction scope includes a series of activated and nonactivated alkenes in moderate to high yields with moderate to high regio- and stereoselectivities.

Pd-catalyzed dehydrogenative cross-coupling of polyfluoroarenes with heteroatom-substituted enones.

The first example of intermolecular regioselective α-arylation of heteroatom-substituted enones with polyfluoroarenes via twofold C-H bond functionalization using a palladium catalyst is reported. This approach provides rapid access to a wide range of α-fluoroarylated enones of interest in life science.

Thioether-Promoted Direct Olefination of Polyfluoroarenes Catalyzed by Palladium

A methyl(phenyl)sulfane-promoted direct olefination of polyfluoroarenes catalyzed by palladium has been reported. With use of this new thioether ligand, a high reaction efficiency and excellent E/Z ratio of desired olefinated polyfluoroarenes were obtained. This represents a first example of thioether promoted oxidative Heck reaction.

Pd-catalyzed oxidative cross-coupling between two electron rich heteroarenes

The transition-metal-catalyzed oxidative cross-coupling between two coupling partners with similar structure and electronic characteristics remains a challenge owing to difficulty in suppressing undesired homo-couplings. We herein report a Pd-catalyzed oxidative cross-coupling between two thiophenes under mild reaction conditions. This approach can also be extended to furans. Some notable advantages of this reaction lie in its synthetic simplicity with the omission of the toxic stannanes coupling partner and excellent functional-group compatibility. The features of this protocol make it an ideal strategy for the construction of a 2,2′-thiophene–thiophene linkage of interest in electronic and optoelectronic materials.

Direct (Het)Arylation of Fluorinated Benzothiadiazoles and Benzotriazole with (Het)Aryl Iodides

A new and controllable method for the preparation of unsymmetrical and symmetrical fluorinated benzothiadiazole (FBT)-arene structures that can be applied in organic optoelectronic materials has been developed. The reaction proceeds under mild reaction conditions with high efficiency and shows excellent functional group compatibility, even toward bromide. Fluorinated benzotriazoles also take part in the reaction.

Selective thienylation of fluorinated benzothiadiazoles and benzotriazoles for organic photovoltaics

An unprecedented example for the selective and efficient synthesis of an FBT–thiophene structural motif via dual C–H functionalization, catalyzed by palladium, has been developed. Fluorinated benzotriazole is also applicable to the reaction. This protocol provides facile access to unsymmetrical and symmetrical thienylated FBTs that can be applied in the development of high performance photovoltaics, in particular in bulk heterojunction (BHJ) solar cells.

Direct olefination of fluorinated benzothiadiazoles: a new entry to optoelectronic materials.

Fluorinated olefin-containing benzothiadiazoles have important applications in optoelectronic materials. Herein, we reported the direct olefination of fluorinated benzothiadiazoles, as catalyzed by palladium. The reaction proceeds under mild reaction conditions and shows high functional-group compatibility. A preliminary study of the properties of the resulting symmetrical and unsymmetrical olefin-containing fluorinated benzothiadiazoles in red-light-emitting dyes has also been conducted.

Catalyst-Free and Visible Light Promoted Trifluoromethylation and Perfluoroalkylation of Uracils and Cytosines

Fluoroalkylated enaminones, such as trifluridine and 5-trifluoromethyluracil, have widespread applications in pharmaceuticals and agrochemicals. Although these kinds of pharmaceutical agent often bear CF3 and perfluoroalkyl motifs in the core structure, access to such analogues typically requires multi-step synthesis. Here, we report a mild, metal-free and operationally simple strategy for the direct perfluoroalkylation of uracils, cytosines and pyridinones through a visible-light induced pathway from perfluoroalkyl iodides. This photochemical transformation features synthetic simplicity, mild reaction conditions without any photoredox catalyst, and high functional group tolerance, providing a facile route for applications in medicinal chemistry.