Olive-Shaped Organic Cages: Synthesis and Remarkable Promotion of Hydrazone Condensation through Encapsulation in
Yan-Yan Xu1, Hong-Kun Liu1, Ze-Kun Wang1
1Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, 2205 Songhu Road, Shanghai 200438, China.
Abstract:
Two organic cages have been prepared in situ in water through the 2 + 3 hydrazone coupling of two pyridinium-derived trialdehydes and oxalohydrazide. The highly water-soluble cages encapsulate and solubilize linear neutral molecules. Such encapsulation has been applied for the promotion of both two- or three-component hydrazone condensation in water. For two-component reactions, the yields of the resulting monohydrazones are increased from 5-10 to 90-96%. For three-component reactions of hydrazinecarbohydrazide with 11 aromatic aldehydes, in the presence of the organic cages, the bihydrazone products can be produced in 88-96% yields. In contrast, without the promotion of the organic cages, 9 of the reactions do not afford the corresponding dihydrazone product.
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