Five- and six-membered cyclic silylated onium ions of group 15 elements I were synthesized by intramolecular cyclization of transient silylium ions II. Silylium ions II were prepared by the hydride transfer reaction from silanes III using trityl cation as hydride acceptor. It was found that smaller ring systems could not be obtained by this approach. In these cases tritylphosphonium ions IV were isolated instead. Cations I and IV were isolated in the form of their tetrakispentafluorphenyl borates and characterized by multinuclear NMR spectroscopy and, in two cases, by X-ray diffraction analysis. Cyclic onium ions I showed no reactivity similar to that of isoelectronic intramolecular borane/phosphane frustrated Lewis pairs (FLPs). The results of DFT computations at the M05-2X level suggest that the strength of the newly formed Si-E linkage is the major reason for inertness of I[B(C6F5)4] versus molecular hydrogen.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/ic502968z | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
"Cation Pool" generated from DMSO and 1,2-dihaloethanes and their application in organic synthesis.
Org Biomol Chem
September 2024
Department of Chemistry, National Institute of Technology, Rourkela, Odisha-769008, India.
Conventionally, carbenium and onium ions are prepared in the presence of nucleophiles due to their instability and transient nature. The nucleophiles that are unstable or inert to the reaction media cannot be used for reaction with the cationic species to access the desired compounds. To overcome these limitations, developing methods for generating organic cations irreversibly in the absence of nucleophiles is essential.
View Article and Find Full Text PDFMechanistic investigation of methanol-to-olefins conversion catalyzed by H-ZSM-5 zeolite: a DFT study.
J Mol Model
July 2024
College of Chemistry, Nankai University, Tianjin, 300071, China.
Context: The mechanisms for the formation of the first C - C bond and lower olefins on methanol to olefins (MTO) conversion on H-ZSM-5 had been focused in dispute. In this paper, density functional theory has been used to study the reaction mechanisms of methanol to olefins on ZSM-5. The configurations of reactants, intermediates, products and transition state of the numerous reactions involved in such a process have been optimized, as well as the elementary reactions related to these configurations were determined by the calculation of corresponding activation energy barriers and reaction heats.
View Article and Find Full Text PDFOrganometallic Ionic Plastic Crystals Incorporating Cationic Half-Sandwich Complexes.
Inorg Chem
August 2024
Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, Hyogo 657-8501, Japan.
Ionic plastic crystals (IPCs), characterized by nearly spherical molecular ions, exhibit remarkable solid-state characteristics including high ionic conductivity. However, most IPCs are organic onium salts. Incorporating organometallic half-sandwich complexes into IPCs is challenging owing to their low-symmetry structures.
View Article and Find Full Text PDFExploiting Visible-Light Induced Radical to Cation Transformation Pathway for Reactivity Enhanced Electrophilic Aromatic Substitution Polymerization of Heteroaromatics.
Macromol Rapid Commun
February 2024
Department of Chemistry, Faculty of Science and Letters, Istanbul Technical University, Maslak, Istanbul, 34469, Turkey.
A straightforward approach is employed to synthesize methylene-bridged poly(hetero aromatic)s based on furan, pyrrole, thiophene, and thiophene derivatives. The process involves an electrophilic aromatic substitution reaction facilitated by a visible light-initiated system consisting of manganese decacarbonyl and an iodonium salt. The approach mainly relies on the formation of halomethylium cation, the attack of this cation to heteroaromatic, regeneration of methylium cation on the heteroaromatic, and reactivity differences between halomethylium and heteroaromatic methylium cations for successful polymerizations.
View Article and Find Full Text PDFIntra- and Intermolecular Cation-π Interactions between Onium Salts and Alkynes/Acetylene: Experimental and Theoretical Insights.
J Org Chem
October 2023
Univ Rouen Normandie, INSA Rouen Normandie, CNRS, Normandie Univ, COBRA UMR 6014, INC3M FR 3038, F-76000 Rouen, France.
Cation-π interactions between various onium salts, alkynes, and acetylene were studied, taking into account the substituents of the triple bond, the nature of the anions, and the polarity of the solvent, through a combination of MP2 calculations and experiments. In an intramolecular setting, these data (including single-crystal X-ray crystallography) concurred with the stability of folded conformers of alkynyl onium salts, even substituted with electron-withdrawing groups. To examine the contribution of these interactions on the alkyne electronic population, a thorough in silico study was carried out using natural bonding orbital analysis of the conformers.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!