RIKEN Center for Emergent Matter Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
Department of Applied Chemistry, Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, 338-8570, Japan.
Chemistry. 2022 Nov 7;28(62):e202201940. doi: 10.1002/chem.202201940. Epub 2022 Sep 8.
The photocyclodimerization of 2-anthracenecarboxylic acid has been extensively studied as a model reaction of asymmetric photochemistry. So far, numerous chiral environments have been employed to control this photoreaction, while the scope of photoreactants has been limited only to 2-anthracenecarboxylic acid and its simple esters and amides. Here, we developed a systematic series of photoreactants (2 a-d) by introducing various substituents to 2-anthracenecarboxylic acid, which showed different reactivities and selectivities depending on the substituents. By using the photoreactants 2 a-d, we evaluated the performance of a chiral environment composed of an amphiphilic amino alcohol (1), where the photocyclodimerization of 2 a-d generally proceeded in excellent regio- and enantioselectivities (71-98 % regio ratio, 76-86 % ee). Furthermore, by reacting 2 a and 2 b together in the chiral environment of 1, we succeeded in the first stereocontrolled cross-photocyclodimerization between two prochiral anthracenes (58 % chemo ratio, 83 % regio ratio, 90 % ee).
2-蒽羧酸的光环二聚反应已被广泛研究，作为不对称光化学的模型反应。到目前为止，已经使用了许多手性环境来控制这种光反应，而光反应物的范围仅局限于 2-蒽羧酸及其简单的酯和酰胺。在这里，我们通过在 2-蒽羧酸上引入各种取代基，开发了一系列系统的光反应物（2a-d），它们的反应性和选择性取决于取代基。通过使用光反应物 2a-d，我们评估了由两亲性氨基醇（1）组成的手性环境的性能，其中 2a-d 的光环二聚化通常以优异的区域和对映选择性进行（71-98%的区域比，76-86%ee）。此外，通过在 1 的手性环境中使 2a 和 2b 一起反应，我们成功地实现了两个前手性蒽的首例立体控制交叉光环二聚化（58%的化学比，83%的区域比，90%ee）。
