A Pd(II) complex of a β-cyclodextrin-based polydentate ligand: an efficient catalyst for the Suzuki reaction in aqueous media
Molecular assembly has become a promising strategy for designing new polydentate ligands. But very often such ligands and their complexes are sparingly soluble in aqueous phase due to their intrinsic hydrophobic character. Pd(II) complexes are good homogeneous catalysts but their poor solubility in aqueous phase may limit their catalytic efficacy in the universal green solvent water. However, solubility related challenges especially in aqueous phase can be mitigated through the formation of inclusion complexes by exploiting the hydrophobic nature of the β-cyclodextrin (β-CD) cavity. Hence, an ionic liquid ChCD (1) was synthesized from β-CD and Choline bromide (ChBr). Next a supramolecular N, N′, O-tridentate ligand 1⊂2 (3) was synthesized by the inclusion of 2,6-diaminopyridine (2) in the hydrophobic β-CD cavity of the ionic liquid ChCD (1) and was well characterized by elemental analysis, UV-visible, FTIR, 1H NMR spectroscopy, etc. The stoichiometry of the inclusion complex 1⊂2 (3) was found to be 1:1 based on UV-visible spectrophotometric study. A new air stable, highly water soluble Pd2+-complex [κ3-N, N′, O-Pd(1⊂2)H2O]OAc (4) was then synthesized from the supramolecular ligand (3) with 1:1 stoichiometry and used as a catalyst for Suzuki cross-coupling reactions in water at ambient temperature with good to excellent yields. The catalyst can be removed and recycled. Additionally, the use of non-toxic solvent water makes the methodology green, sustainable, and economically viable.
Publisher URL: http://www.tandfonline.com/doi/full/10.1080/00958972.2017.1378812
Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.
Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.