The [3+2] cycloaddition reaction of a tungsten-containing carbonyl ylide with methyl vinyl ether and the insertion reactions of the nonstabilized carbene complex intermediates produced have been investigated through the use of B3LYP density functional theory. The [3+2] cycloaddition reaction of the tungsten-containing carbonyl ylide has been proven to proceed concertedly, reversibly, and with high endo selectivity. The intermolecular Si-H insertion reactions of the carbene complex intermediates have been proven to be favored over the intramolecular C-H insertion, in good agreement with experimental results. Moreover, the kinetic endo/exo ratio of the [3+2] cycloaddition reaction has been shown to determine the endo/exo selectivity of the Si-H insertion products. In addition, secondary orbital interactions involving the benzene ring and the carbonyl ligand on the metal center have turned out to strongly influence the high endo selectivity of the [3+2] cycloaddition reaction with methyl vinyl ether.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/chem.200901033 | DOI Listing |
Org Lett
January 2025
Institute of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan.
Multiple Diels-Alder reactions are a powerful method to construct large asymmetric scaffolds, but these reactions often produce numerous isomers. We now report a triple Diels-Alder reaction between a cyclic furan trimer and -substituted maleimides, achieving selective synthesis of a single asymmetric tris-adduct. The stereoselectivity of cycloaddition to π-extended furan derivatives was clarified by the experimental analysis of intermediates and theoretical calculations.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, c/Maria Aurèlia Capmany 69, 17003 Girona, Catalonia, Spain.
Both silicon and carbon are elements located in group 14 on the periodic table. Despite some similarities between these two elements, differences in reactivity are important, and whereas carbon is a central element in all known forms of life, silicon is barely found in biological systems. Here, we investigate the Diels-Alder cycloaddition reaction of cyclopentadiene (CP) and cyclopentasildiene (CP) with fullerenes C, Li@C, Si, and Li@Si using density functional theory methods.
View Article and Find Full Text PDFChem Soc Rev
January 2025
Pingyuan Laboratory, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, 453007, Henan, P. R. China.
The use of olefins in the construction of cyclic compounds represents a powerful strategy for advancing the pharmaceutical industry. Photocycloaddition has attracted significant interest from chemists due to its ability to exploit simple and readily available olefins along with their reaction patterns under mild conditions. Moreover, the sustainable and versatile pathways for generating highly reactive intermediates can greatly enrich both substrate diversity and reaction patterns.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg, Institute for Inorganic Chemistry, GERMANY.
We report a selective one-step synthesis of perarylated borirenes by reaction of antiaromatic boroles with 1,4-diarylbuta-1,3-diynes. Mechanistic studies, both experimental and computational, reveal key intermediates, including boranorbornadiene and 7-borabicyclo[4.1.
View Article and Find Full Text PDFJ Org Chem
January 2025
State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, 15 Yu Cai Road, Guilin 541004, China.
A cascade reaction of Pd(II)/dppben-catalyzed [3 + 2] cycloaddition of -aryl nitrones with allenoates and sequential reduction has been developed for the synthesis of functionalized benzazepines bearing three contiguous carbon stereocenters in moderate to good yields ranging from 15 to 82% and high diastereoselectivity. The obtained benzazepines could be converted into various benzazepine scaffolds, and an estrone-derived benzazepine scaffold was prepared over four steps from estrone. More importantly, chiral benzazepine bearing three contiguous carbon stereocenters could be obtained in 88% ee value with chiral auxiliary.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!