Department of Chemistry, University of California , Irvine, California 92697-2025, United States.
J Am Chem Soc. 2018 Feb 28;140(8):3091-3102. doi: 10.1021/jacs.7b13799. Epub 2018 Feb 20.
The first total synthesis of a chromodorolide marine diterpenoid is described. The core of the diterpenoid is constructed by a bimolecular radical addition/cyclization/fragmentation cascade that unites two complex fragments and forms two C-C bonds and four contiguous stereogenic centers of (-)-chromodorolide B in a single step. This coupling step is initiated by visible-light photocatalytic fragmentation of a redox-active ester, which can be accomplished in the presence of an iridium or a less-precious electron-rich dicyanobenzene photocatalyst, and employs equimolar amounts of the two addends. Computational studies guided the development of this central step of the synthesis and provide insight into the origin of the observed stereoselectivity.
本文描述了一种色多醇类海洋二萜的首次全合成。该二萜的核心结构由双分子自由基加成/环化/断裂级联反应构建，通过该反应一步构建了两个复杂片段，形成了两个 C-C 键和四个连续的 (-)-色多醇 B 的立体中心。此偶联步骤由氧化还原活性酯的可见光光催化断裂引发，该反应可以在铱或非贵金属富电子二氰基苯光催化剂的存在下完成，并且使用等摩尔量的两种反应物。计算研究指导了这一合成关键步骤的发展，并深入了解了观察到的立体选择性的起源。
