Herein, we report a novel copper-catalyzed imidoylative cross-coupling/cyclocondensation reaction between 2-isocyanobenzoates and amines efficiently producing quinazolin-4-ones. The reaction utilizes Cu(II) acetate as an environmentally benign catalyst in combination with a mild base and proceeds well in anisole, a recommended, sustainable solvent. Additionally, the reaction does not require dry conditions or inert atmospheres for optimal performance. The scope of this isocyanide insertion reaction is rather broad, tolerating various functionalized isocyanobenzoates and a range of substituted amines, although the use of aromatic amines as nucleophiles requires microwave heating.
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http://dx.doi.org/10.1021/acs.joc.0c00771 | DOI Listing |
Chemistry
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
November 2024
Center for Catalysis and Florida Center for Heterocyclic Chemistry, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States.
Iron hydrides are proposed reactive intermediates for N and CO conversion in industrial and biological processes. Here, we report a reactivity study of a low-coordinate di(μ-hydrido)diiron(II) complex, Fe(μ-H), where is a bis(β-diketiminate) cyclophane, with isocyanides, which have electronic structures related to N and CO. The reaction outcome is influenced by the isocyanide substituent, with 2,6-xylyl isocyanide leading to H loss, to form a bis(μ-1,1-isocyanide)diiron(I) complex, whereas all of the other tested isocyanides insert into the Fe-H bond to give (μ-1,2-iminoformyl) complexes.
View Article and Find Full Text PDFChem Commun (Camb)
October 2024
Organic Chemistry and Catalysis, Institute for Sustainable and Circular Chemistry, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands.
A formal carbene-transfer reaction from an isolated nickelacyclobutane to an isocyanide to form a ketenimine is reported. DFT calculations support a stepwise 1,1-insertion/fragmentation pathway without a carbene intermediate. This unusual reactivity suggests a potential new role as "carbene reservoir" for nickelacyclobutanes, which are typically seen as intermediates in catalytic cyclopropanation.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
September 2024
Department of Chemistry: Metalorganics and Inorganic Materials, Technische Universität Berlin, Strasse des 17. Juni 115, Sekr. C2, 10623, Berlin, Germany.
The facile reaction of the SiPh-bridged bis-silylene (LSi:)SiPh (L=PhC(NBu)) with diphenylacetylene affords the unprecedented 1,2,3-trisilacyclopentadiene (LSi)(PhC)SiPh 1 with a hypercoordinate λSi-λSi double bond. Compound 1 is very oxophilic and consumes three molar equivalents of inert NO to form the bicyclic oxygenation product 2 through O-atom insertion in the Si=Si and Si-Si bonds. Strikingly, 1 can completely split the C≡O bonds of carbon monoxide under ambient conditions (1 atm, room temperature), yielding the 1,3-disilacyclopentadiene 3, representing the first hypercoordinate example of a cyclosilene with a λSi-λC double bond.
View Article and Find Full Text PDFOrganometallics
August 2024
Grupo de Química Organometálica, Departamento de Química Inorgánica, Facultad de Química, Universidad de Murcia, Murcia E-30071, Spain.
The polynuclear complex [{μ-1,4,,″-CH{C(H)=N(Bu)}-2,5}{Pd(μ-OAc)}] () reacts with tbbpy (4,4'-di--butyl-2,2'-bipyridine) and TlOTf to form the dinuclear complex [{μ-1,4,,″-CH{C(H)=N(Bu)}-2,5}{Pd(tbbpy)}] (). The hydrolysis of with acetic acid in a 5:1 acetone/water mixture, in the presence of two equivalents of tbbpy and excess NaX (X = Br, I), yields the dipalladated terephthalaldehyde complexes [CH{PdX(tbbpy)}-1,4-(CHO)-2,5] [X = Br (), X = I ()], which are the first fully characterized complexes of this type. The reaction of with CO results in the insertion of CO into both aryl-Pd bonds, forming [CH{C(O){PdX(tbbpy)}}-1,4-(CHO)-2,5] [X = Br (), X = I ()], which are the first examples of complexes with CO inserted into two separate aryl-metal bonds involving the same ligand.
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