Li Wen-Tao, Hu Meng-Yang, Xiong Jun-Wen, Zhang Xin-Yu, Zhu Shou-Fei
Frontiers Science Center for New Organic Matter, State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University Tianjin 300071 China.
Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192 China
Chem Sci. 2022 Jun 13;13(26):7873-7879. doi: 10.1039/d2sc02160a. eCollection 2022 Jul 6.
Although research on iron-catalysed reactions has recently achieved significant progress, the activity and selectivity of iron catalysts are generally inferior to those of noble-metal catalysts. The development of new iron-catalysed reactions, especially those in which iron catalysts exhibit superior activity or selectivity to other catalysts, is the key to promote iron catalysis. Herein, we report the first protocol for iron-catalysed hydroalumination of internal alkynes. Specifically, in the presence of iron catalysts bearing 2,9-diaryl-1,10-phenanthroline ligands, internal alkynes were stereo- and regioselectively hydroaluminated with the commercially available reagent diisobutylaluminum hydride. Compared with other metal-catalysed alkyne hydroalumination reactions reported in the literature, the iron-catalysed protocol has the following advantages: unusual amino-group-directed regioselectivity, a wide substrate scope, good functional group tolerance, high selectivity, and mild reaction conditions. The alkenylaluminum products prepared in this way could undergo a diverse array of transformations, and were used for the synthesis of bioactive compounds. The current study expands the scope of iron catalysis, provides a new efficient access to alkenylaluminum, discloses the origin of the superiority of iron catalysts, and thus may inspire further studies in related fields.
尽管近年来铁催化反应的研究取得了显著进展，但铁催化剂的活性和选择性通常低于贵金属催化剂。开发新型铁催化反应，特别是那些铁催化剂表现出优于其他催化剂的活性或选择性的反应，是推动铁催化发展的关键。在此，我们报道了首例铁催化的内炔烃氢化铝化反应。具体而言，在带有2,9-二芳基-1,10-菲咯啉配体的铁催化剂存在下，内炔烃与市售试剂二异丁基氢化铝发生立体和区域选择性氢化铝化反应。与文献中报道的其他金属催化的炔烃氢化铝化反应相比，铁催化的方法具有以下优点：不寻常的氨基导向区域选择性、广泛的底物范围、良好的官能团耐受性、高选择性以及温和的反应条件。以这种方式制备的烯基铝产物可以进行多种转化，并用于生物活性化合物的合成。当前的研究扩展了铁催化的范围，提供了一种新的高效合成烯基铝的方法，揭示了铁催化剂优越性的来源，因此可能会激发相关领域的进一步研究。
