Yu Wan-Lei, Ren Zi-Gang, Ma Ke-Xing, Yang Hui-Qing, Yang Jun-Jie, Zheng Haixue, Wu Wangsuo, Xu Peng-Fei
State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University Lanzhou 730000 China
Frontiers Science Center for Rare Isotopes, Lanzhou University Lanzhou China.
Chem Sci. 2022 Jun 15;13(26):7947-7954. doi: 10.1039/d2sc02291e. eCollection 2022 Jul 6.
The transformations that allow the direct removal of hydrogen from their corresponding saturated counterparts by the dehydrogenative strategy are a dream reaction that has remained largely underexplored. In this report, a straightforward and robust cobaloxime-catalyzed photochemical dehydrogenation strategy intramolecular HAT is described for the first time. The reaction proceeds through an intramolecular radical translocation followed by the cobalt assisted dehydrogenation without needing any other external photosensitizers, noble-metals or oxidants. With this approach, a series of valuable unsaturated compounds such as α,β-unsaturated amides, enamides and allylic and homoallylic sulfonamides were obtained in moderate to excellent yields with good chemo- and regioselectivities, and the synthetic versatility was demonstrated by a range of transformations. And mechanistic studies of the method are discussed.
通过脱氢策略直接从相应的饱和类似物中去除氢的转化反应是一个一直未得到充分探索的理想反应。在本报告中，首次描述了一种简单且稳健的钴肟催化光化学脱氢策略——分子内氢原子转移。该反应通过分子内自由基转移，随后在钴的辅助下进行脱氢，无需任何其他外部光敏剂、贵金属或氧化剂。通过这种方法，以中等至优异的产率获得了一系列有价值的不饱和化合物，如α,β-不饱和酰胺、烯酰胺以及烯丙基和高烯丙基磺酰胺，具有良好的化学和区域选择性，并且通过一系列转化展示了合成通用性。此外，还讨论了该方法的机理研究。
