Department of Chemistry, Renmin University of China, Beijing, 100872, P. R. China.
Roy and Diana Vagelos Laboratories, Penn/Merck Laboratory for High-Throughput Experimentation, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA 19104-6323, USA.
Chemistry. 2022 Jun 27;28(36):e202200441. doi: 10.1002/chem.202200441. Epub 2022 May 19.
The first Rh -catalyzed, directed decarbonylative C2-H alkenylation of imidazoles with readily available alkenyl carboxylic acids is reported. The reaction proceeds in a highly regio- and stereoselective manner, providing efficient access to C2-alkenylated imidazoles that are generally inaccessible by known C-H alkenylation methods. This transformation accommodates a wide range of alkenyl carboxylic acids, including challenging conjugated polyene carboxylic acids, and diversely decorated imidazoles with high functional group compatibility. The presence of a removable pyrimidine directing group and the use of a bidentate phosphine ligand are pivotal to the success of the catalytic reaction. This process is also suitable for benzimidazoles. Importantly, the scalability and diversification of the products highlight the potential of this protocol in practical applications. Detailed experimental and computational studies provide important insights into the underlying reaction mechanism.
首次报道了首例 Rh 催化的、导向的、去羰基化的咪唑与易得的烯基羧酸的 C2-H 烯基化反应。该反应以高度区域和立体选择性的方式进行，提供了高效的 C2-烯基化咪唑的途径，这些咪唑通常无法通过已知的 C-H 烯基化方法获得。这种转化可以适应广泛的烯基羧酸，包括具有挑战性的共轭多烯羧酸，以及具有高官能团兼容性的各种取代咪唑。可去除的嘧啶导向基团的存在和双齿膦配体的使用对催化反应的成功至关重要。该过程也适用于苯并咪唑。重要的是，产物的可扩展性和多样化突出了该协议在实际应用中的潜力。详细的实验和计算研究为基础反应机制提供了重要的见解。
