-selective C-H functionalization of free phenols by metal carbenoids is rather challenging due to the generally more favorable competing O-H insertion. Herein, with the use of the combination of Rh(II) and a Xantphos ligand as the catalyst, a novel multicomponent reaction of free phenols, diazoesters, and allylic carbonates was successfully developed, affording a wide variety of phenol derivatives, bearing an all-carbon quaternary center and a synthetically useful allylic unit. This reaction is likely to occur through a tandem process of carbene-induced -selective C-H functionalization, followed by Rh(II)/Xantphos-catalyzed allylation. The distinctive reactivity of -selective C-H rather than O-H insertion for the carbenoid intermediate, combined with features of excellent functional group compatibility, high atom and step economy, and ease in further diversification of the products, might render this protocol highly attractive in facile functionalization of unprotected phenols.
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http://dx.doi.org/10.1021/acscentsci.2c00004 | DOI Listing |
Angew Chem Int Ed Engl
January 2025
University of Basel, Department of Chemistry, St. Johanns-Ring 19, 4056, Basel, SWITZERLAND.
Despite the growing importance of planar chiral macrocyclophanes owing to their unique properties in different areas of chemistry, methods that are effective in controlling their planar chirality are restricted to certain molecular scaffolds. Herein, we report the first Pd(0)-catalyzed enantioselective intermolecular C-H arylation that induces planar chirality by installing bulky aryl groups through dynamic kinetic resolution (DKR). A computer-assisted approach allowed a fine-tuning of the structure of the employed chiral bifunctional phosphine-carboxylate ligands to achieve high enantioselectivities.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, P. R. China.
As an efficient, sustainable, and environmentally friendly semiconductor material, covalent organic frameworks (COFs) can generate hydrogen peroxide (HO) by photocatalysis, attracting wide attention in recent years. Herein, the effects of hydroxyl, methoxyl, and vinyl groups of imide-linked two-dimensional (2D) COFs on the photocatalytic production of HO were studied theoretically and experimentally. The introduction of vinyl groups greatly promotes the photogenerated charge separation and migration of COFs, providing more oxygen adsorption sites, stronger proton affinity, and lower intermediate binding energy, which effectively facilitates the rapid conversion of oxygen to HO.
View Article and Find Full Text PDFJ Org Chem
January 2025
Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210023, China.
We herein report a Rh(III)-catalyzed C-H bond coupling of -chloroimines with maleimides, in which the [4 + 2] annulation and dehydrogenative annulation processes can be selectively achieved by simply adjusting the reaction conditions. This protocol is compatible with various functional groups, shows exquisite selectivity, and presents a concise synthetic procedure to respective products in moderate to good yields. With all these merits, this strategy may be applicable in the construction of related azaheterocyclic skeletons.
View Article and Find Full Text PDFJ Nanobiotechnology
January 2025
Graduate School of Biotechnology, and College of Life Science, Kyung Hee University, Yongin-Si, 17104, Gyeonggi-Do, Republic of Korea.
Background: Nanodrugs play a crucial role in biomedical applications by enhancing drug delivery. To address safety and toxicity concerns associated with nanoparticles, lipid-nanocarrier-based drug delivery systems have emerged as a promising approach for developing next-generation smart nanomedicines. Ginseng has traditionally been used for various therapeutic purposes, including antiviral activity.
View Article and Find Full Text PDFChem Sci
January 2025
Department of Chemistry, Indian Institute of Technology Hauz Khas Delhi New Delhi 110016 India
The direct transformation of methane into C oxygenates such as acetic acid selectively using molecular oxygen (O) is a significant challenge due to the chemical inertness of methane, the difficulty of methane C-H bond activation/C-C bond coupling and the thermodynamically favored over-oxidation. In this study, we have successfully developed a porous aluminium metal-organic framework (MOF)-supported single-site mono-copper(ii) hydroxyl catalyst [MIL-53(Al)-Cu(OH)], which is efficient in directly oxidizing methane to acetic acid in water at 175 °C with a remarkable selectivity using only O. This heterogeneous catalyst achieved an exceptional acetic acid productivity of 11 796 mmol mol h in 9.
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