forming a newcarbon-carbonbond while preserving the carbon-halogen bond has been developed. A cheap and readily available Ni-catalyst is employed to generate nitrogen containing heterocycles in good to excellent yields and the procedure is readily scalable. The more readily available aryl bromides were also cyclized with the addition of potassium iodide to generate the respective alkyl iodides. A rare
已开发出一种新型镍催化的环异构化反应,可在保留碳 - 卤素键的同时形成新的碳 - 碳键。使用廉价且易于获得的 Ni 催化剂以良好至极好的产率生成含氮杂环,并且该过程易于扩展。更容易获得的芳基溴化物也通过加入碘化钾环化以生成相应的烷基碘化物。使用双膦和一氧化二膦的罕见双配体系统用于获得对映体富集的产品。
Photoexcited Nickel-Catalyzed Carbohalogenation
作者:Ramon Arora、Mark Lautens
DOI:10.1021/acscatal.3c05994
日期:2024.2.2
light-catalyzed carbohalogenation reaction is reported. A nickel catalyst and an inexpensive phosphine ligand promote the reaction of aryl iodides and aryl bromides with π systems to enable the construction of a library of halogenated heterocyclic scaffolds. Mechanistic studies provide insight regarding fundamental steps of the catalytic cycle, including the reversible C–X bond formation via deuterium labeling
A novel visible-light-induced radical cascade bromocyclization of N-arylacrylamides has been accomplished. This reaction overcomes the overbromination at the benzene rings suffered in traditional electrophilic reactions, thus enabling the first highly chemoselective synthesis of valuable 3-bromomethyloxindoles. The combination of pyridine and anhydrous medium is identified as the key factor for the