环丙烯研究新进展

Recent Advances of Cyclopropene Chemistry

环丙烯类化合物是自然界中可能存在的最小的不饱和环状化合物,它独特的结构和电性使其在有机合成中有着非常广泛的用途.环丙烯类化合物有着很大的环张力,具有很高的张力能和反应活性,一直以来都作为一类明星分子得到了化学家们的广泛关注.尤其是近年来当金属有机化合物介入环丙烯化学,通过各种加成反应,环加成反应,开环反应等,可作为一个三碳结构单元用于构筑各类有机化合物.本文则主要从环丙烯的合成、环丙烯的转化和参与的反应,以及环丙烯的应用三个方面概述了2011年至今关于环丙烯的最新研究进展.

Cyclopropenes are the smallest unsaturated carbocyclic but readily accessible compounds with high strain energy（54.1 kcal/mol）, which resulting in the high activity of cyclopropenes in reactions. Cyclopropenes have been a hot research topic for many years, since the synthesis, transformations, and applications of cyclopropenes have drawn attentions of chemists, and a series of interesting and significant cyclopropene chemistry have been demonstrated. Especially when transition-metal-catalysts were introduced into cyclopropene chemistry, a number of unprecedented transformations through addition reactions, cycloadditions, and ring-opening reactions have been developed. Several excellent reviews focused on transition metal chemistry of cyclopropenes and enantiomerically enriched cyclopropene have been published before 2011. However, some very important progresses on cyclopropene chemistry have been achieved in the next several years. This review will cover the literatures from 2011 to 2015, including the synthesis, transformations and applications of cyclopropenes. The paper included five chapters： the first part is the introduction of the article; in the second chapter, the recent advances in preparation of cyclopropenes were described; next, in the third part, the recent progress of transformations of cyclopropenes was discussed. The reactions of cyclopropenes were devided into two categories： 1） the transformations in which the ring of cyclopropene was opened by cycloaddition and cycloisomerization reactions. In some reactions an unsaturated metal carbene mechanism was involved, and subsequent insertion reaction, isomerization, or coupling reactions led to diverse functionalized products. In these reactions, cyclopropene serves as a very important 3-carbon building block; 2） the chemical transformations in which the three-membered ring was retained is an important pathway to multisubsitituted cyclopropane derivatives; the forth part summarized the recent applications of cyclopropenes, mainly focused on its specialities as bioorthogonal chemical reporters. Cyclopropene showed great significances in affinity-based protein labeling and synthesis of photo-cross-linkers suitable for live-cell imaging; in the last part, we summed up the article and made an outlook on the future development of cyclopropene chemistry.