Paternò-Büchi反应的区域选择性

Regioselectivity in the Paternò-Büchi Reaction

Paternò-Büchi(P-B)反应,即羰基-烯的[2+2]光环化加成反应,利用其特殊的区域及立体选择性可以合成一些结构精巧的取代氧杂环丁烷。随着P-B反应在有机合成中越来越广泛的应用,人们对P-B反应的区域选择性的研究也越来越深入。在P-B反应发现之初,人们一直用“最稳定的双自由基规则”解释其区域选择性,这一规则对有些体系却不适用,近年来有人开始运用“自旋化学”理论来解释区域选择性。本论文结合作者的研究工作,评述了近年来P-B反应的区域选择性的研究进展,重点阐述了反应温度、反应物的取代基对P-B反应区域选择性的影响及其规律。

The Paternò-Büchi （P-B） reaction, which is a photochemical [ 2 ＋ 2 ] cycloaddition of carbonyl compounds with alkenes, is used to construct some substituted oxetanes by taking advantage of its special stereo- and regioselectivity. With the more and more applications in organic synthesis of the P-B reaction, its regioselectivity has attracted more and more attention. The most stable biradical rule, which was put forward at the beginning of the discovery of the P-B reaction, was used to explain its regioselectivity. However, it was not applicable for some systems. People began to apply spin chemistry to explain the regioselectivity recently. We have summarized the recent progress in studies of the regioselectivity for the P-B reaction in this paper, and especially focused on the temperature and substituent effects on the regioselectivity.