Dimethyl carbonate and dimethyl oxalate are competitive products of the carbonylation reaction of methyl nitrite (MN) under Pd-based catalysts. The chemo-selectivity is influenced not just by the thermodynamic constraints of reaction conditions but also by the electronic structures of catalysts. Lewis acid sites are extensively employed to modulate the electronic structures of Pd active sites for kinetic carbonate production, but their precise role remains unclear. Herein, we employed a combination of reaction kinetic, in situ DRIFTS experiments and DFT calculation, unveiling the indispensable role of Lewis acid sites in activating MN and facilitating the transfer of *OCH3 species, which is the key to obtain the kinetic carbonate outcome. The molecular understanding reveals the cooperation of Pd center and Lewis acid sites in directing selectivity towards carbonate product, which enables the rational design of higher-performance catalysts.
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http://dx.doi.org/10.1002/chem.202500295 | DOI Listing |
Chemistry
March 2025
Chinese Academy of Sciences Fujian Institute of Research on the Structure of Matter, State Key Laboratory of Structural Chemistry, CHINA.
Dimethyl carbonate and dimethyl oxalate are competitive products of the carbonylation reaction of methyl nitrite (MN) under Pd-based catalysts. The chemo-selectivity is influenced not just by the thermodynamic constraints of reaction conditions but also by the electronic structures of catalysts. Lewis acid sites are extensively employed to modulate the electronic structures of Pd active sites for kinetic carbonate production, but their precise role remains unclear.
View Article and Find Full Text PDFJ Am Chem Soc
March 2025
Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, Guangdong Basic Research Center of Excellence for Functional Molecular Engineering, School of Chemistry, IGCME, Sun Yat-sen University, Guangzhou 510275, China.
Nitroso compounds, R-N═O, containing N═O double bonds are ubiquitous and widely utilized in organic synthesis. In contrast, heavier congeners of nitroso compounds, namely pnictinidene chalcogenides R-Pn = E (Pn = P, As, Sb, Bi; E = O, S, Se, Te), are highly reactive and scarce. They have been stabilized in the coordination sphere of Lewis acid/base or by pronounced contribution from resonance structures, whereas free species with unperturbed pnictogen-chalcogen double bonds remains elusive.
View Article and Find Full Text PDFJ Phys Chem Lett
March 2025
Department of Chemistry, University of Reading, Reading RG6 6DX, U.K.
Liquid-phase ds post-transition metal anions, such as [SnCl], appear in a range of applications with a focus on catalysis and material preparation. However, little is known about their electronic structure and how it relates to reactivity. Using X-ray photoelectron spectroscopy and calculations, we demonstrate that liquid-phase ds post-transition metal anions can act as dual-mode Lewis bases, interacting through the metal center and/or the ligands, with the interaction mode depending on the identity of the Lewis acid/electron acceptor.
View Article and Find Full Text PDFInorg Chem
March 2025
Department of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States.
Diethylenetriaminepentaacetic acid (DTPA) is a frequently used chelator in the nuclear and medical industries, especially for the complexation of trivalent actinides. However, structural data on these complexes in the solid-state have long remained elusive. Herein, a detailed structural analysis of the presented crystal structures of [C(NH)][Nd(DTPA)]·HO and [C(NH)][Am(DTPA)]·HO, where [C(NH)] is guanidinium, details the subtle differences in the Lewis acidity between a lanthanide/actinide pair of similar ionic sizes.
View Article and Find Full Text PDFJ Org Chem
March 2025
Department of Chemistry, Indian Institute of Technology, Kanpur 208016, India.
A simple one-pot, two-step strategy for the synthesis of three-dimensional (3D) polyheterocyclic -oxindoles by Lewis-acid-catalyzed Friedel-Crafts type -3 alkylation of indoles regioselective nucleophilic ring opening of -epoxyoxindoles, followed by -TSA-catalyzed Pictet-Spengler reaction with aldehydes in up to 98% yield and 1.4:1 diastereomeric ratio has been developed.
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