Discovery and Mechanistic Study of Al<sup>III</sup>-Catalyzed Transamidation of Tertiary Amides
作者:Justin M. Hoerter、Karin M. Otte、Samuel H. Gellman、Qiang Cui、Shannon S. Stahl
DOI:10.1021/ja0762994
日期:2008.1.1
turnover-limiting step involves intramolecular nucleophilic attack of an amido ligand on the coordinated carboxamide or subsequent rearrangement (intramolecular ligand substitution) of the tetrahedral intermediate. Fundamental mechanistic differences between these tertiary transamidation reactions and previously characterized transamidations involving secondary amides and primary amines suggest that tertiary
羧酰胺的 CN 键的断裂通常需要苛刻的条件。该研究表明,三(酰胺)Al(III) 催化剂,如 Al2(NMe2)6,可促进叔羧酰胺与仲胺的轻松平衡控制转酰胺化。通过动力学、光谱和密度泛函理论 (DFT) 计算方法研究了这些反应的机制。催化剂静止状态由三(酰氨基)Al(III)二聚体和单体三(酰氨基)Al(III)-甲酰胺加合物的平衡混合物组成,并且转换限制步骤涉及酰氨基配体的分子内亲核攻击四面体中间体的配位甲酰胺或随后的重排(分子内配体取代)。