Using a Carbazole Derivative as a Photocatalyst in the Dehalogenation of Aryl Halides

Date

2020-05-12

Journal Title

Journal ISSN

Volume Title

Publisher

Office of Undergraduate Research and Inquiry, The University of Tampa

Abstract

Photoredox catalysis allows chemists to perform single-electron transformations through light excitation of a photocatalyst, which is either metal complex or organic molecule. This process is important compared to traditional single-electron transformations because it is selective, performed under mild conditions, generates less waste, and requires less toxic reagents. The purpose of this research was to determine if the molecule 9-mesityl-3,6-bis(4-methoxyphenyl)-9H-carbazole could be used as a photocatalyst. This carbazole derivative would be useful as a photocatalysts due to it being affordable, metal-free, and exhibiting unique redox properties. Here in, the carbazole derivative was demonstrated to work as a photocatalyst in the dehalogenation of aryl halides in the presence of an amine as a hydrogen donor. The reaction was first optimized using 4-bromobenzonitrile as a substrate. Once optimized, the 4-bromobenzonitrile was converted into the desired product, benzonitrile, in 88% yield after 48 hours. The method was then applied towards other aryl halide substrates. The substrates with electron withdrawing groups, such as 4-bromoacetophenone or 4-chlorobenzonitrile, were converted to their corresponding products in higher yields, whereas substrates without these groups only produced their desired products in low yields.

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Keywords

Criminology, Undergraduate Research, Photoredox catalysis

Citation

DOI