Gannarapu Malla Reddy, Imai Takanori, Iwaki Kentaro, Tsuzuki Seiji, Shibata Norio
Department of Nanopharmaceutical Sciences & Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya, 466-8555, Japan.
Research Center for Computational Design of Advanced Functional Materials, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, 305-8568, Japan.
Commun Chem. 2021 Nov 18;4(1):158. doi: 10.1038/s42004-021-00596-x.
Controlling the sequence of the three consecutive reactive carbon centres of Cu-allenylidene remains a challenge. One of the impressive achievements in this area is the Cu-catalyzed annulation of 4-ethynyl benzoxazinanones, which are transformed into zwitterionic Cu-stabilized allenylidenes that are trapped by interceptors to provide the annulation products. In principle, the reaction proceeds via a preferential γ-attack, while annulation reactions via an α- or β-attack are infrequent. Herein, we describe a method for controlling the annulation mode, by the manipulation of a CF or CH substituent, to make it proceed via either a γ-attack or an α- or β-attack. The annulation of CF-substituted substrates with sulfamate-imines furnished densely functionalized N-heterocycles with excellent enantioselectivity via a cascade of an internal β-attack and an external α-attack. CH-variants were transformed into different heterocycles that possess a spiral skeleton, via a cascade of an internal β-attack and a hydride α-migration followed by a Diels-Alder reaction.
控制铜亚丙二烯中三个连续反应性碳中心的顺序仍然是一项挑战。该领域令人瞩目的成就之一是铜催化的4-乙炔基苯并恶嗪酮的环化反应，该反应将其转化为两性离子铜稳定的亚丙二烯，后者被截获剂捕获以提供环化产物。原则上，反应通过优先的γ-进攻进行，而通过α-或β-进攻的环化反应则很少见。在此，我们描述了一种通过操纵CF或CH取代基来控制环化模式的方法，以使反应通过γ-进攻或α-或β-进攻进行。CF取代的底物与氨基磺酸亚胺的环化反应通过内部β-进攻和外部α-进攻的级联反应，以优异的对映选择性提供了功能密集的N-杂环化合物。CH变体通过内部β-进攻和氢化物α-迁移的级联反应，随后进行狄尔斯-阿尔德反应，转化为具有螺旋骨架的不同杂环化合物。
