Titanium-Promoted Cross-Coupling for the Selective Synthesis of Polysubstituted, Conjugated Amides
作者:Vinoth Kumar Chenniappan、Ronald J. Rahaim
DOI:10.1021/acs.orglett.6b02537
日期:2016.10.7
α,β-Unsaturated amides are important building blocks and are key structural elements in a number of biologically active natural products. Despite their importance and prevalence, few methods exist to prepare conjugated amides directly and modularly. To address this gap, a titanium-promoted coupling of alkynes and isocyanates has been developed. The method is highly stereoselective, producing only the
α,β-不饱和酰胺是重要的结构单元,并且是许多具有生物活性的天然产物中的关键结构元素。尽管它们的重要性和普遍性,但几乎没有直接或模块化制备共轭酰胺的方法。为了解决这个空白,已经开发了钛促进的炔烃和异氰酸酯的偶联。该方法是高度立体选择性的,对于包含空间偏倚的不对称内部炔烃,仅产生具有良好的化学选择性和区域选择性(> 95/5)的E异构体。由炔和异氰酸酯的偶联形成的反应性钛环戊烯中间体另外与各种亲电试剂反应以得到四取代的烯酰胺。