Organic Macromolecular Chemistry, Saarland University, Campus Saarbrücken C4 2, 66123 Saarbrücken, Germany.
Beilstein J Org Chem. 2013 Sep 12;9:1858-66. doi: 10.3762/bjoc.9.217. eCollection 2013.
The formation of soluble 1:2 complexes within hydrophilic γ-cyclodextrin (γ-CD) thioethers allows to perform photodimerizations of aromatic guests under controlled, homogenous reaction conditions. The quantum yields for unsubstituted anthracene, acenaphthylene, and coumarin complexed in these γ-CD thioethers were found to be up to 10 times higher than in the non-complexed state. The configuration of the photoproduct reflected the configuration of the dimeric inclusion complex of the guest. Anti-parallel orientation of acenaphthylene within the CD cavity led to the exclusive formation of the anti photo-dimer in quantitative yield. Parallel orientation of coumarin within the complex of a CD thioether led to the formation of the syn head-to-head dimer. The degree of complexation of coumarin could be increased by employing the salting out effect.
在亲水性γ-环糊精（γ-CD）硫醚内形成可溶性 1:2 配合物，可在受控、均相反应条件下进行芳族客体的光二聚反应。在这些γ-CD 硫醚中配合的未取代蒽、苊烯和香豆素的量子产率比非配合状态下高 10 倍。光产物的构型反映了客体二聚体包合配合物的构型。在 CD 腔体内，苊烯的反平行取向导致反式光二聚体以定量产率的形式优先形成。在 CD 硫醚配合物内，香豆素的平行取向导致顺式头对头二聚体的形成。通过盐析效应，可以增加香豆素的配合程度。
