Department of Chemistry, Yale University, 225 Prospect Street, New Haven, CT 06520-8107, USA.
Angew Chem Int Ed Engl. 2018 May 22;57(21):6251-6255. doi: 10.1002/anie.201802963. Epub 2018 Apr 23.
Catalyst control over reactions that produce multiple stereoisomers is a challenge in synthesis. Control over reactions that involve stereogenic elements remote from one another is particularly uncommon. Additionally, catalytic reactions that address both stereogenic carbon centers and an element of axial chirality are also rare. Reported herein is a catalytic approach to each stereoisomer of a scaffold containing a stereogenic center remote from an axis of chirality. Newly developed peptidyl copper complexes catalyze an unprecedented remote desymmetrization involving enantioselective C-N bond-forming cross-coupling. Then, chiral phosphoric acid catalysts set an axis of chirality through an unprecedented atroposelective cyclodehydration to form a heterocycle with high diastereoselectivity. The application of chiral copper complexes and phosphoric acids provides access to each stereoisomer of a framework with two different elements of stereogenicity.
催化剂控制产生多个立体异构体的反应是合成中的一个挑战。控制涉及彼此远离的立体元素的反应特别少见。此外,同时涉及立体碳中心和轴向手性元素的催化反应也很少见。本文报道了一种含有远离手性轴的立体中心的支架的每个立体异构体的催化方法。新开发的肽铜配合物催化前所未有的远程去对称化,涉及对映选择性 C-N 键形成交叉偶联。然后,手性磷酸催化剂通过前所未有的非对映选择性环脱水形成具有高非对映选择性的杂环来设置手性轴。手性铜配合物和磷酸的应用为具有两个不同立体中心的骨架的每个立体异构体提供了途径。