期刊
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
卷 60, 期 18, 页码 10359-10365出版社
WILEY-V C H VERLAG GMBH
DOI: 10.1002/anie.202101499
关键词
amides; host-guest systems; isonitriles; molecular containers; mono-functionalization
资金
- Gobierno de Espana MICIN/AEI/FEDER, UE [CTQ2017-84319-P, CEX2019-000925-S]
- CERCA Programme/Generalitat de Catalunya
- AGAUR [2017 SGR 1123]
- Chinese Research Council [2017-06870013]
- MECD [FPU14/01016]
This study reports the binding of an octa-pyridinium super aryl-extended calix[4]pyrrole receptor with difunctional aliphatic guests in water. Through experimental characterization, it was found that the receptor acts as both a sequestering and supramolecular protecting group in the reactions.
We report binding studies of an octa-pyridinium super aryl-extended calix[4]pyrrole receptor with neutral difunctional aliphatic guests in water. The guests have terminal isonitrile and formamide groups, and the complexes display an inclusion binding geometry and 1:1 stoichiometry. Using H-1 NMR titrations and ITC experiments, we characterized the dissimilar thermodynamic and kinetic properties of the complexes. The bis-isonitriles possess independent reacting groups, however, in the presence of 1 equiv of the receptor the hydrolysis reaction produces mixtures of non-statistical composition and a significant decrease in reaction rates. The selectivity for the mono-formamide product is specially enhanced in the case of the bis-isonitrile having a spacer with five methylene groups. The analysis of the kinetic data suggests that the observed modifications in reaction rates and selectivity are related to the formation of highly stable inclusion complexes in which the isonitrile is hidden from bulk water molecules. The concentration of the reacting substrates in the bulk solution is substantially reduced by binding to the receptor. In turn, the hydrolysis rates of the isonitrile groups for the bound substrates are slower than in the bulk solution. The receptor acts as both a sequestering and supramolecular protecting group.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据