The diarylstannylenes, Sn(AriPr4)2 and Sn(AriPr6)2, (AriPr4 = C6H3-2,6-(C6H3-2,6-iPr2)2, AriPr6 = C6H3-2,6-(C6H2-2,4,6-iPr3)2), undergo a facile migratory insertion reaction with ethylene at 60 °C to afford the alkyl aryl stannylenes AriPr4SnCH2CH2AriPr4 and AriPr6SnCH2CH2AriPr6 which were characterized via1H, 13C and 119Sn NMR, UV-vis and IR spectroscopy, as well as by X-ray crystallography. Quantum mechanical calculations were performed, and two potential mechanisms were identified, with a migratory insertion reaction pathyway being energetically preferred.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1039/c8cc08488b | DOI Listing |
Chem Commun (Camb)
December 2024
Key Laboratory of Precision and Intelligent Chemistry, Department of Chemistry, University of Science and Technology of China, Hefei 230026, China.
A method for synthesizing allenylselenides has been developed using readily available propargyl carbonate and phenylselenol. The reaction is catalyzed by Ni(II) and proceeds a migratory insertion and β-oxygen elimination mechanism. Due to the strong interaction between Se and Ni leading to catalyst deactivation, zinc salt was used to mitigate the deleterious effects of Se anions on the catalyst, thereby facilitating the successful synthesis of the target products.
View Article and Find Full Text PDFThe extravasation of polymorphonuclear neutrophils (PMNs) is a critical component of the innate immune response that involves transendothelial migration (TEM) and interstitial migration. TEM-mediated interactions between PMNs and vascular endothelial cells (VECs) trigger a cascade of biochemical and mechanobiological signals whose effects on interstitial migration are currently unclear. To address this question, we cultured human VECs on a fibronectin-treated transwell insert to model the endothelium and basement membrane, loaded PMN-like differentiated HL60 (dHL-60) cells in the upper chamber of the insert, and collected the PMNs that crossed the membrane-supported monolayer from the lower chamber.
View Article and Find Full Text PDFJ Org Chem
December 2024
Department of Basic Education, Shanxi Agricultural University, Jinzhong, Shanxi 030801, P. R. China.
DFT calculations have been performed to gain insight into the mechanism of hydrocarbonylation of olefins and the origin of regio- and chemoselectivity. It is shown that the most feasible mechanism involves five steps: (i) decomposition of acetic formic anhydride, (ii) hydropalladation of olefins, (iii) CO migratory insertion, (iv) iodide-assisted acetate-formate exchange, and (v) formylation or carboxylation. Importantly, carboxylation proceeds via the decomposition of anhydride, followed by reductive elimination instead of direct hydrolysis of anhydride.
View Article and Find Full Text PDFJ Surg Case Rep
November 2024
Department of Surgery, The Jewish Hospital - Mercy Health, 4777 East Galbraith Rd, Cincinnati, OH 45236, United States.
Biliary stent insertion during endoscopic retrograde cholangiopancreatography is a therapeutic intervention to relieve obstruction and facilitate flow through the biliary tree. In rare circumstances, these stents can migrate and result in distal gastrointestinal perforation, which may necessitate endoscopic or surgical intervention. We report a case involving a 79-year-old female who presented with peritonitis due to sigmoid colon perforation following biliary stent migration.
View Article and Find Full Text PDFChem Sci
December 2024
Anhui Laboratory of Clean Catalytic Engineering, Anhui Laboratory of Functional Coordinated Complexes for Materials Chemistry and Application, College of Chemical and Environmental Engineering, Anhui Polytechnic University Wuhu 241000 Anhui P. R. China
The rare-earth metal dialkyl complexes (κ-L)RE(CHSiMe)·(THF) [RE = Lu(1a), Yb(1b), Er(1c), Y(1d), Dy(1e)] (L = 1-(2--CHNCHCH)-3-(2,6-PrCHN[double bond, length as m-dash]CH)-CHN) and the rare-earth metal monoalkyl complexes (κ-L)RE(CHSiMe)·(THF) [ = 0, RE = Lu(2a), Yb(2b); = 1, Er(2c), Y(2d), Dy(2e)], (κ-L)RE(CHSiMe)·THF [RE = Yb(3a), Er(3b), Y(3c), Dy(3d), Gd(3e)] (L = 1-(2--CHNCHCH)-3-(AdN[double bond, length as m-dash]CH)-CHN) (Ad = adamantyl, CH) have been synthesized and fully characterized. These complexes feature chelate ligands having a conjugated system (-C[double bond, length as m-dash]C-C[double bond, length as m-dash]N) with an sp carbon, which enables both electrophilic and nucleophilic carbon centres to be directly connected to the highly electrophilic rare-earth metal ions. The reactions of these complexes with different pyridine derivatives have been systematically investigated with the discovery of reactivity patterns distinct from those of previously reported transition metal complexes.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!