Department of Chemical Science and Engineering and ‡Department of Chemistry, Tokyo Institute of Technology , O-okayama, Meguro-ku, Tokyo 152-8550, Japan.
Org Lett. 2017 Jun 2;19(11):2993-2996. doi: 10.1021/acs.orglett.7b01231. Epub 2017 May 17.
The synthesis of C- and C-symmetrical [8]cycloparaphenylene (CPP)-octacarboxylates has been achieved via macrocyclization by the rhodium-catalyzed intermolecular stepwise cross-cyclotrimerization and subsequent reductive aromatization. The C-symmetrical octa-tert-butyl [8]CPP-octacarboxylate forms a dimer in which eight ester moieties face each other. The dimers are aligned so as to make a one-dimensional column with a channel structure inside. Both absorption and fluorescence maxima of [8]CPP-octacarboxylates in CHCl were significantly blue-shifted compared to those of [8]CPP due to the presence of eight electron-withdrawing ester moieties.
通过铑催化的分子间逐步交叉三聚化和随后的还原芳构化，实现了 C-和 C-对称[8]环对苯撑（CPP）-辛羧酸酯的合成。C-对称辛基[8]CPP-辛羧酸酯形成二聚体，其中八个酯基彼此相对。这些二聚体排列成一维柱状结构，内部有一个通道结构。由于存在八个吸电子酯基，[8]CPP-辛羧酸酯在 CHCl 中的吸收和荧光最大值与[8]CPP 相比明显蓝移。
