Halogen bonding, the non-covalent interaction of Lewis bases with an electron-deficient region of halogen substituents, received increased attention recently. Consequently, the design and evaluation of numerous halogen-containing species as halogen bond donors have been subject to intense research. More recently, organoiodine compounds at the iodine(III) state have been receiving growing attention in the field. Due to their electronic and structural properties, they provide access to unique binding modes. For this reason, our groups have been involved in the development of such compounds, in the quantification of their halogen bonding strength (through the evaluation of their Lewis acidities), as well as in the evaluation of their activities as catalysts in several model reactions. This account will describe these contributions.
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http://dx.doi.org/10.1002/tcr.202100119 | DOI Listing |
J Am Chem Soc
December 2024
Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration & Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR 999077, China.
Catalytic enantioselective substitution of the readily available racemic α-halo carbonyl compounds by nitrogen nucleophiles represents one of the most convenient and direct approaches to access enantioenriched α-amino carbonyl compounds. Distinct from the two available strategies involving radicals and enolate ions, herein we have developed a new protocol featuring an electronically opposite way to weaken/cleave the carbon-halogen bond. A suitable chiral anion-based catalyst enables effective asymmetric control over the key positively charged intermediates.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
School of Materials Science and Engineering, Peking University, Beijing 100871, P. R. China.
Potassium-iodine batteries show great promise as alternatives for next-generation battery technology, owing to their high power density and environmental sustainability. Nevertheless, they suffer from polyiodide dissolution and the multistep electrode fabrication process, which leads to severe performance degradation and limitations in mass-market adoption. Herein, we report a simple "solution-adsorption" strategy for scale-up production of TiC(OH)-wrapped carbon nanotube paper (CNP), as an economic host for strengthening the iodine encapsulation.
View Article and Find Full Text PDFNano Lett
December 2024
State Key Laboratory of Solidification Processing, Center for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University and Shaanxi Joint Laboratory of Graphene (NPU), Xi'an 710072, P. R. China.
Dion-Jacobson (DJ) perovskites are promising alternatives for Ruddlesden-Popper (RP) perovskites to fabricate blue perovskite light-emitting diodes (PeLEDs) due to their favorable structural and charge properties. However, the relatively weak hydrogen bond between the bridging diammonium group and perovskite poses huge challenges for regulating crystallization and defect density, leading to an undesirable film quality and device performance. Herein, we report the successful optimization of DJ perovskite films by introducing a new type of cesium octafluoroadipate (CsOFAA) precursor, which could strongly anchor the perovskite through coordination bonds and halogen-halogen bonds.
View Article and Find Full Text PDFBeilstein J Org Chem
December 2024
Department of Chemical and Geological Sciences, University of Cagliari, S.S. 554, bivio per Sestu, 09042 Monserrato (CA), Italy.
The rising popularity of bioconjugate therapeutics has led to growing interest in late-stage functionalization (LSF) of peptide scaffolds. α,β-Unsaturated amino acids like dehydroalanine (Dha) derivatives have emerged as particularly useful structures, as the electron-deficient olefin moiety can engage in late-stage functionalization reactions, like a Giese-type reaction. Cheap and widely available building blocks like organohalides can be converted into alkyl radicals by means of photoinduced silane-mediated halogen-atom transfer (XAT) to offer a mild and straightforward methodology of alkylation.
View Article and Find Full Text PDFJ Org Chem
December 2024
Department of Chemistry, Oklahoma State University, 107 Physical Sciences, Stillwater, Oklahoma 74078, United States.
While charge-transfer complexes involving halogen-bonding interactions have emerged as an alternative strategy for the photogeneration of carbon radicals, examples using (fluoro)alkyl bromides are limited. This report describes a dual catalytic approach for radical generation from α-bromodifluoroesters and amides under visible-light irradiation. Mechanistic studies suggest that the reaction proceeds through bromide displacement using a catalytic iodide salt, generating a C-I bond that can be engaged by our halogen-bonding photocatalysis platform.
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