Iron-Catalyzed Trimerization of Terminal Alkynes Enabled by Pyrimidinediimine Ligands: A Regioselective Method for the Synthesis of 1,3,5-Substituted Arenes
作者:Julianna S. Doll、Robert Eichelmann、Leif E. Hertwig、Thilo Bender、Vincenz J. Kohler、Eckhard Bill、Hubert Wadepohl、Dragoş-Adrian Roşca
DOI:10.1021/acscatal.1c00978
日期:2021.5.7
to a functional-group-tolerant methodology for the catalytic trimerization of terminal aliphatic alkynes. Remarkably, in contrast to established alkyne trimerization protocols, the 1,3,5-substituted arenes are the main reaction products. Preliminary mechanistic investigations suggest that the enhanced π-acidity of the pyrimidine ring, combined with the hemilability of the imine groups coordinated to
众所周知的吡啶二亚胺(PDI)铁络合物的基于嘧啶的类似物的开发,使得能够使用功能基团耐受的方法对末端脂肪族炔烃进行催化三聚。值得注意的是,与已建立的炔三聚方案相反,1,3,5-取代的芳烃是主要的反应产物。初步的机械研究表明,嘧啶环的增强的π-酸度,与与铁中心配位的亚胺基团的半胱氨酸结合,促进了这种转变。催化循环的入口是可分离的二氮铁络合物。催化反应通过1,3-取代的金属环进行,这解释了所观察到的1,3,5-区域选择性。可以分离出这样的金属环,代表稀有的1,