Studies on the Mechanism of Action of 2-Formyl-4-pyrrolidinopyridine: Isolation and Characterization of a Reactive Intermediate
作者:Tarek Sammakia、T. Brian Hurley
DOI:10.1021/jo982281n
日期:1999.6.1
action of 2-formyl-4-pyrrolidinopyridine (FPP, 1a) which is a catalyst for the hydroxyl-directed methanolysis of alpha-hydroxy esters. This species was initially designed to act as a nucleophilic catalyst; however, we have ruled out a nucleophilic mechanism by examining the activity of 6-substituted-FPP derivatives. These compounds are more hindered in the vicinity of the pyridine nitrogen than FPP itself
本文介绍了2-甲酰基-4-吡咯烷二吡啶(FPP,1a)的作用机理,该催化剂是α-羟基酯的羟基定向甲醇分解的催化剂。该物种最初被设计用作亲核催化剂。但是,我们通过检查6-取代的FPP衍生物的活性,排除了亲核机理。与FPP本身相比,这些化合物在吡啶氮附近的受阻更大,但也是更具活性的催化剂。此外,发现对硝基苯酚(一种弱酸)的存在会加速催化反应。这些结果与亲核催化机理不一致。我们提供证据表明该反应反而是通过二氧戊环中间体10进行的。二氧戊环酮10可以通过在不存在甲醇的情况下在氯仿中用FPP处理乙醇酸的对硝基苯酯或五氟苯基酯来获得。当经受催化反应的条件时,已经分离,表征并显示出动力学上的能力。