研究目的
Developing a new protocol for C5-selective C–H trifluoromethylation of 8-aminoquinolines using photoredox catalysis under mild conditions.
研究成果
The developed photoredox catalysis protocol enables efficient and selective C5-trifluoromethylation of 8-aminoquinolines under mild, metal-free conditions using environmental benign solvents. It offers advantages over existing methods, such as simplicity and operability at room temperature in air. The mechanism involves a trifluoromethyl radical pathway, as confirmed by control experiments. Future work will explore applications to other trifluoromethylation reactions.
研究不足
The reaction yields are moderate to good (35-60%), with some substrates showing lower yields due to steric effects or multisubstitution. The protocol requires specific equipment like LED lights and may not be applicable to all quinoline derivatives. Optimization is needed for broader substrate scope and higher efficiency.
1：Experimental Design and Method Selection:
The study employed photoredox catalysis with Eosin Y as the photocatalyst, using visible light from blue LEDs to facilitate the reaction. The methodology involved optimizing reaction conditions through screening catalysts, oxidants, and solvents to achieve high selectivity and yield for C5-trifluoromethylation.
2：Sample Selection and Data Sources:
Various 8-aminoquinoline derivatives were synthesized and used as substrates, with CF3SO2Na as the trifluoromethyl source. Samples were selected based on structural diversity to test the generality of the protocol.
3：List of Experimental Equipment and Materials:
Equipment included a magnetic stir bar, vial, 63 W blue LED lamps (Kessil A360WE LED Aquarium Light), NMR spectrometers (400, 101, 376 MHz), Fourier transform infrared spectrophotometer, and HRMS with ESI. Materials included Eosin Y, Na2S2O8, CF3SO2Na, solvents (MeCN, H2O, etc.), and silica gel for chromatography.
4：Experimental Procedures and Operational Workflow:
Reactions were conducted in air by adding substrates, reagents, and solvent to a vial, irradiating with blue LEDs for 20 hours at approximately 46°C, followed by workup involving evaporation, extraction with EtOAc, washing with brine, drying over Na2SO4, and purification by column chromatography.
5：Data Analysis Methods:
Products were characterized using 1H, 13C, and 19F NMR spectroscopy, IR spectroscopy, and HRMS to confirm structures and yields.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
