The Pd-catalyzed cross-coupling of phenyl esters and alkyl boranes is disclosed. Two reaction modes are rendered accessible in a selective fashion by interchange of the catalyst. With a Pd-NHC system, alkyl ketones can be prepared in good yields via a Suzuki-Miyaura reaction proceeding by activation of the C(acyl)-O bond. Use of a Pd-dcype catalyst enables alkylated arenes to be synthesized by a modified pathway with extrusion of CO. Applications of this divergent coupling strategy and the origin of the switchable selectivity are discussed.
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http://dx.doi.org/10.1021/acs.orglett.8b01646 | DOI Listing |
Angew Chem Int Ed Engl
January 2025
RIKEN: Rikagaku Kenkyujo, Center for Sustainable Resource Science, 2-1 Hirosawa, 351-0198, Wako, JAPAN.
Transition-metal-catalyzed selective and efficient activation of an inert C-H bond in an organic substrate is of importance for the development of streamlined synthetic methodologies. An attractive approach is the design of a metal catalyst capable of recognizing an organic substrate through noncovalent interactions to control reactivity and selectivity. We report here a spirobipyridine ligand that bears a hydroxy group that recognizes pyridine and quinoline substrates through hydrogen bonding, and in combination with an iridium catalyst enables site-selective C-H borylation.
View Article and Find Full Text PDFChemistry
January 2025
Indian Institute of Science Education and Research Bhopal Department of Chemistry, Chemistry, Room No. 226, Academic Block - 2, Indore By-pass Road, Bhauri, 462066, Bhopal, INDIA.
Unraveling the electronic structure of metal complexes can bring various catalytic possibilities for hydrogen evolution reaction (HER). However, the electronic effect of metal and ligands modulating and switching the reaction center for HER has yet to be comprehensively analyzed. Herein, we report nickel selenoether electrocatalysts which show tunable reaction centers (nickel or ligand) for HER using mild weak acetic acid in less deprotonating DMF solvent.
View Article and Find Full Text PDFEur J Pharm Biopharm
January 2025
Department of Pharmaceutical Technology, University of Regensburg 93053 Regensburg, Bavaria, Germany. Electronic address:
The utilization of targeted nanoparticles as a selective drug delivery system is a powerful tool to increase the amount of active substance reaching the target site. This can increase therapeutic efficacy while reducing adverse drug effects. However, nanoparticles face several challenges: upon injection, the immediate adhesion of plasma proteins may mask targeting ligands, thereby diminishing the target cell selectivity.
View Article and Find Full Text PDFOrg Lett
January 2025
Division of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan.
1,1-Difluoroallenes underwent regioselective [2 + 2] and [3 + 2] cycloadditions with aldehydes using Au(I) catalysts. An AuCl catalyst enabled an α,β-selective [2 + 2] cycloaddition of 1,1-difluoroallenes, yielding ()-3-alkylidene-2,2-difluorooxetanes. Conversely, an AuCl(IPr)-AgSbF catalyst facilitated an α,γ-selective [3 + 2] cycloaddition, followed by dehydrofluorination to produce aromatized 2-fluorofurans.
View Article and Find Full Text PDFMater Horiz
January 2025
State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China.
Adhesion-switchable ultralow-hysteresis polymer ionogels are highly demanded in soft electronics to avoid debonding damage and signal distortion, yet the design and fabrication of such ionogels are challenging. Herein, we propose a novel method to design switchable adhesive ionogels by using binary ionic solvents with two opposite-affinity ionic components. The obtained ionogels exhibit moisture-induced phase separation, facilitating switchable adhesion with a high detaching efficiency (>99%).
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