Olive-Shaped Organic Cages: Synthesis and Remarkable Promotion of Hydrazone Condensation through Encapsulation in Water

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.

Porous dynamic covalent polymers as promising reversal agents for heparin anticoagulants

“…Compound A 1 was prepared according to the reported method. 59 The synthetic details for compounds A 2 , A 3 , H 1 and H 2 are provided in the ESI †. All the compounds are highly soluble in water (>10 mM).…”

Benzylic C(sp3)–H Bonds Play the Dual Role of Starting Material and Oxidation Inhibitor for Hydrazides in the Electrochemical Synthesis of Hydrazones

“…13 C­{ 1 H} NMR (125 MHz, DMSO- d 6 + CDCl 3 ) δ 156.1, 140.9, 135.0, 129.6, 128.9, 127.3. Known compound …”

Covalent Organic Cages in Catalysis

“…Now, the encapsulated guest could easily undergo chemical conversions inside the confined hydrophobic pockets of an organic cage. In this regard, Li et al constructed charged [2 + 3] organic cages ( POC-23 and 24 ) from dynamic hydrazone condensation reactions of trispyridinium-based trialdehydes and diacylhydrazines in aqueous medium (Figure a) . Both of the charged organic cages were found to form host–guest inclusion complexes (1:1) upon adding organic guest molecules in water.…”