羧基活化转化的机理及其在化学与生物体系中的应用

The mechanism of carboxyl activated-transfer reactions and its applications in chemistry and biology

羧基活化转化反应是有机化学的重要问题之一,同时在生物体系中也广泛存在,研究其机理具有广泛的意义.本文结合相关物理有机化学和生物化学原理,用势能面图从动力学和热力学2方面对该过程的过渡态和中间体进行分析讨论,同时考查了缩合过程使用催化剂与否对该过程的影响,提出各种羧基活化转化反应机理的一般规律.结合这一原理对比了化学活化与生物活化的异同,并对其在不同体系中的应用进行了评述,以期对发展新型羧基活化方式与物理有机化学教学提供有意义的参考.

The activation and transfer reaction on carboxyl group is not only an important topic in organic chemistry, but also a vital issue in biochemical systems. Understanding the details of these reactions could help investigators develop new synthetic methods, syntheze functional proteins and design new drugs or inhibitors. In this article, potential energy surfaces based on general physical organic and biochemical princeples are employed to analyze the structures and properties the transition states or intermediates in these reactions, as well as catalysts involved situations. A tetrahedron intermediate mediated two-step addition-elimination reaction mechanism is propused to be the most possible reaction process and Hammond postulate is used to determine the relative energy value of different transition states and intermediates. During the reaction, those activating groups which can effectively stablized the tetrahedron intermediates and eliminating from the centra carbon atom easily are illustrated to be better carboxyl group activating reagents, as the similar situations in catalysts of carboxyl activated reactions. Different cases in chemistry and biology of carboxyl activated-transfer reactions are compared and proved to be follow the same rules. And the applications of carboxyl activated-transfer reactions in chemical synthesis of peptides and biochemical process are also discussed. The analysis and comments of this review might serve researchers as meaningful reference on devoloping new carboxyl activated-transfer reactions.