非对称氮杂环丁烷的区域选择性开环反应

发布时间：2018-05-01 10:40

本文选题：氮杂环丁烷 + 开环反应　；参考：《化学进展》2017年Z2期

【摘要】：本文系统总结了非对称氮杂环丁烷的区域选择性开环反应。氮杂环丁烷的开环反应主要包括亲核开环、Stevens重排扩环及消除开环反应等。其中,亲核开环反应是氮杂环丁烷的主要开环方式。开环的区域选择性与氮杂环丁烷取代基结构密切相关。氮杂环丁烷相对比较稳定,其开环通常需要路易斯酸催化或者先转化成季铵盐才可以发生,因此,其开环反应的区域选择性受电子效应的影响比较明显。邻位带有不饱和官能团的氮杂环丁烷及其季铵盐一般发生氮原子与带有不饱和官能团的碳原子之间化学键的断裂,这是因为如芳基、烯基、氰基、酰基、甲酸酯基和甲酰胺基等不饱和官能团的共轭效应可以稳定其连接的碳原子在开环时形成的过渡态或者中间体,使该C—N键更容易断裂。如亲核开环反应,亲核试剂一般进攻芳甲位、烯丙位或连有氰基或甲酸酯基或甲酰胺基的邻位碳原子,电子效应起主要作用。对于2-烷基取代的氮杂环丁烷及其季铵盐,大位阻或者亲核性强的亲核试剂的开环反应一般发生在位阻小的氮邻位碳原子,空间效应起主要作用。分子内的亲核开环反应主要受反应过程中环大小的控制,一般有利于经过三元环、五元环、六元环和七元环过程开环得到开环产物。氮杂环丁烷是一类非常重要的含氮杂环化合物,通过总结和分析氮杂环丁烷的开环反应及其区域选择性,可以更好地认识和利用这类反应,通过有效地预测和控制开环反应的方向,来制备所需的有机化合物。希望本文能够促进氮杂环丁烷开环反应在有机化学中的发展与应用。
[Abstract]:The region selective ring opening reaction of asymmetric heterocyclic butane was systematically summarized in this paper. The ring opening reactions of azacyclic butane mainly include nucleophilic ring opening Stevens rearrangement and elimination of ring opening reaction. The nucleophilic ring-opening reaction is the main ring-opening mode of nitrogen heterocyclic butane. The region selectivity of ring opening is closely related to the substituent structure of azacyclic butane. Nitrogen heterocyclic butane is relatively stable, its ring opening usually requires Lewis acid to catalyze or convert to quaternary ammonium salt, therefore, the region selectivity of ring opening reaction is obviously affected by electron effect. N-heterocyclic butane and its quaternary ammonium salts with unsaturated functional groups generally break the chemical bonds between nitrogen atoms and carbon atoms with unsaturated functional groups, such as aryl, alkenyl, cyanide, acyl, The conjugation effect of unsaturated functional groups such as formate group and formamide group can stabilize the transition state or intermediate formed by the connected carbon atoms during the opening of the ring, which makes the C-N bond easier to break. For nucleophilic ring-opening reactions, nucleophilic reagents generally attack aromatics, allylic sites or o-carbon atoms with cyanide or formate groups or formamide groups, and the electron effect plays a major role. For 2-alkyl-substituted N-heterocyclic butane and its quaternary ammonium salts, the ring-opening reactions of large steric resistance or strong nucleophilic reagents generally occur in nitrogen-ortho-carbon atoms with small in-situ hindrance, and the spatial effect plays a major role. The nucleophilic ring opening reaction in the molecule is mainly controlled by the size of the ring in the reaction process, and it is generally favorable to obtain the ring opening product through the three ring, five member ring, six member ring and seven member ring process. Heterocyclic butane is a very important class of nitrogen-containing heterocyclic compounds, which can be better recognized and utilized by summarizing and analyzing the ring-opening reactions and their regioselectivity of aza-heterocyclic butane. The desired organic compounds were prepared by effectively predicting and controlling the direction of the ring-opening reaction. It is hoped that this paper will promote the development and application of ring-opening reaction of azacyclic butane in organic chemistry.
【作者单位】：北京化工大学理学院有机化学系化工资源有效利用国家重点实验室;
【基金】：国家重大基础研究项目(No.2013CB328905) 国家自然科学基金项目(No.21372025,21172017)资助~~
【分类号】：O621.25

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