Selective Binding and Isomerization of Oximes in a Self-Assembled Capsule

Kuppusamy Kanagaraj; Rui Wang; Ming-Kai Zhao; Pablo Ballester; Julius Rebek Jr; Yang Yu

doi:10.1021/jacs.2c12907

Selective Binding and Isomerization of Oximes in a Self-Assembled Capsule

J Am Chem Soc. 2023 Mar 15;145(10):5816-5823. doi: 10.1021/jacs.2c12907. Epub 2023 Mar 1.

Authors

Kuppusamy Kanagaraj¹, Rui Wang¹, Ming-Kai Zhao¹, Pablo Ballester^{2

3}, Julius Rebek Jr^{1

4}, Yang Yu¹

Affiliations

¹ Center for Supramolecular Chemistry & Catalysis and Department of Chemistry, College of Science, Shanghai University, Shanghai 200444, China.
² Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology (BIST), 43007 Tarragona, Spain.
³ Catalan Institution for Research and Advanced Studies (ICREA), 08010 Barcelona, Spain.
⁴ Skaggs Institute for Chemical Biology and Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States.

PMID: 36857099
DOI: 10.1021/jacs.2c12907

Abstract

A series of straight-chain (C7-C13) alkyl-O-methyl aldoximes (R-C(H)═NOMe) were synthesized with various functional groups at the remote ends (alkenes, halogen, -COOH, and NH₂). Their isomers about the C═N bond showed ∼60-40% E-Z-ratio in organic solutions. Surprisingly, their confinement in a water-soluble capsule with benzoselenodiazole walls shows high selectivity for the cis-/Z-isomer. Their relative affinities for the chalcogen-bonded capsule at room temperature depend mainly on the guest chain length and functional groups. A chain length of 14 heavy atoms showed especially high E- to Z-isomer selectivity (>99%) and was used in separation. The E-Z isomerization occurred only in the capsular cavity at room temperature and was accelerated 10-fold by sonication. The Z-isomer selective binding, separation, and E-Z isomerization are supported by NMR, DOSY, and computational studies.