A solid-supported isocyanide ligand was developed to destroy active metathesis catalysts and to remove ruthenium byproducts from metathesis reactions. This method was able to significantly reduce the concentration of residual ruthenium from the organic products of several alkene and ene-yne metathesis reactions, under a variety of different conditions.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/ol402339e | DOI Listing |
Chemistry
December 2024
Southern University of Science and Technology, Chemistry, 1088 Xueyuan Avenue, 518055, Shenzhen, CHINA.
The convergent total synthesis of ixabepilone and its analogues in a 13-step longest linear sequence is reported. The crucial chiral centers at challenging C3-O, C8-C and C15-N positions on the scaffold of the ixabepilone were installed via highly efficient asymmetric hydrogenations (up to 95% yield and up to 99% e.e.
View Article and Find Full Text PDFJ Org Chem
December 2024
Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan.
(-)-Exiguolide is a marine macrolide natural product with potent anticancer activity. In this study, the total synthesis of exiguolide stereoisomers, (9)-exiguolide, (9,13)-exiguolide, and (9,13,19)-exiguolide, was achieved by capitalizing on our macrocyclization/transannular pyran cyclization strategy. The impact of the stereochemical permutation on the reactivity of advanced intermediates, the conformation of the macrocyclic skeleton, and the antiproliferative activity against human cancer cells were investigated in detail.
View Article and Find Full Text PDFChemistry
December 2024
Universiteit Utrecht, Chemistry, Universiteitsweg 99, 3584CG, Utrecht, NETHERLANDS, KINGDOM OF THE.
Nickelacyclobutanes are reactive intermediates in catalytic cycles involving cyclopropanation and insertion reactions. The stoichiometric study of these intermediates has shown that their reactivity is highly influenced by the coordination environment of the nickel center. A pentacoordinated nickelacyclobutane embedded in a diphosphine pincer ligand has been shown to selectively undergo various reactions with exogenous ligands, including [2+2] cycloreversion and carbene transfer to an isocyanide.
View Article and Find Full Text PDFInorg Chem
December 2024
Physical Institute, Karlsruhe Institut of Technology (KIT) Campus South, Wolfgang-Gaede-Str. 1, Karlsruhe 76131, Germany.
The dinuclear β-diketiminato complex [LClDy(μ-Cl)DyL(THF)] () (L = {2,6-PrCH-NC(Me)CHC(Me)N-2,6-PrCH}) was obtained by reaction of DyCl with KL in a molar ratio of 1:1 and used for the preparation of the mixed-ligand complex [LDy(μ-3,5-Cat)] () by salt metathesis reaction with 3,5-CatK (3,5-Cat -3,5-di--butyl-catecholate). Reactions of 3,5-CatNa with [LLnCl(THF)] (Ln = Dy, Y) ligated with the less bulky ligand L = {2,4,6-MeCH-NC(Me)CHC(Me)N-2,4,6-MeCH} afforded the mixed-ligand THF-containing complexes [LLn(μ-3,5-Cat)(THF)] (Ln = Dy (), Y ()). All new complexes were fully characterized, and the solid-state structures were determined by single-crystal X-ray diffraction.
View Article and Find Full Text PDFPhys Chem Chem Phys
December 2024
Department of Chemistry, CMS College Kottayam (Autonomous) Mahatma Gandhi University, Kottayam, Kerala, 686001, India.
A detailed theoretical study delving into the molecular mechanisms of the Ullmann-type -arylation reactions catalyzed by manganese and zinc metal ions has been investigated with the aid of the density functional theory (DFT) method. In contrast to the redox-active mechanisms proposed for classical Ullmann-type condensation reaction, a redox-neutral mechanism involving σ-bond metathesis emerged as the most appealing pathway for the investigated high-valent Mn(II) and Zn(II)-catalyzed -arylation reactions. The mechanism remains invariant with respect to the nature of the central metal, ligand, base, This unusuality in the mechanism has been dissected by considering three cases: ligand-free and ligand-assisted Mn(II)-catalyzed -arylation reaction and ligand-assisted Zn(II)-catalyzed -arylation reactions.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!