Abstract EN:

The native cyclodextrins (CDs) display many free hydroxyl groups (each sugar unit bears 3 hydroxyl groups) and these hydroxyl groups could be substituted by other groups (this process called functionalization of CDs) in some appropriate ways, thus providing cyclodextrins with a much wider range of potential applications. Hence, the task of functionalization of CDs is attractive to chemists.In this thesis, we summarized numbers of selective functionalization methods for CDs both on their primary and their secondary rim, and particularly the Diisobutylaluminium hydride (DIBAL-H) induced selective debenzylation method.This powerful method was chosen for the achievement of hepta-differentiation of -CD on its primary rim. There were two strategies—azide reduction/debenzylation and thioacetate reduction/debenzylation, that have been envisaged for the hepta-differentiation of -CD. Both azide and thioacetate displayed interesting results for the DIBAL-H selective debenzylation system, but both of them owned their disadvantages. As for the azide, when 3 Nitrogens were introduced on the primary rim of -CD, the debenzylation reaction would not occur even with large quantities of DIBAL-H (>50 eq), therefore, this strategy stopped at the tetra-differentiated stage. As for the thioacetate, the Sulphur substituted derivatives were not stable enough and that brought significant yield lost problem. To overcome this problem, carefully controlled reaction conditions counteracted most yield lost problems. Finally, the thioacetate strategy allowed us to achieve the hepta-differentiation of -CD.