339 research outputs found
Ruthenium(II)-Catalyzed C–H Oxygenations of Reusable Sulfoximine Benzamides
No full textC-H oxygenations of synthetically meaningful sulfoximine benzamides were accomplished by a versatile ruthenium catalysis regime. The ruthenium(II) catalyst was characterized by excellent mono- and chemoselectivity as well as positional selectivity via facile base-assisted intramolecular electrophilic substitution-type (BIES) C-H activation. The synthetic utility of the approach was reflected by high functional group tolerance and sulfoximine removal in a traceless fashion
‐Selective Cobalt Catalysis
No full textCationic cobalt complexes enable unprecedented cobalt-catalyzed C-H/C-C functionalizations with unique selectivity features. The versatile cobalt catalyst proved broadly applicable, enabled efficient C-H/C-C cleavage at room temperature, and delivered Z-alkenes with excellent diastereocontrol
ChemInform Abstract: Manganese‐Catalyzed Synthesis of cis‐β‐Amino Acid Esters Through Organometallic C—H Activation of Ketimines.
No full textCobalt-catalyzed C–H cyanations: Insights into the reaction mechanism and the role of London dispersion
No full textCarboxylate-assisted cobalt(III)-catalyzed C–H cyanations are highly efficient processes for the synthesis of (hetero)aromatic nitriles. We have now analyzed the cyanation of differently substituted 2-phenylpyridines in detail computationally by density functional theory and also experimentally. Based on our investigations, we propose a plausible reaction mechanism for this transformation that is in line with the experimental observations. Additional calculations, including NCIPLOT, dispersion interaction densities, and local energy decomposition analysis, for the model cyanation of 2-phenylpyridine furthermore highlight that London dispersion is an important factor that enables this challenging C–H transformation. Nonbonding interactions between the Cp* ligand and aromatic and C–H-rich fragments of other ligands at the cobalt center significantly contribute to a stabilization of cobalt intermediates and transition states
Full Selectivity Control in Cobalt(III)-Catalyzed C−H Alkylations by Switching of the C−H Activation Mechanism
No full textKetone-Assisted Ruthenium(II)-Catalyzed C-H Imidation: Access to Primary Aminoketones by Weak Coordination
No full textThe ruthenium(II)-catalyzed intermolecular C-H imidation with weakly coordinating ketones provided step-economical access to synthetically useful primary aminophenones. The azide-free C-H imidation strategy occurred with ample scope and excellent functional group tolerance to efficiently deliver densely substituted aminophenones
Manganese-Catalyzed Synthesis of cis-beta-Amino Acid Esters through Organometallic C-H Activation of Ketimines
No full textManganese-catalyzed C-H functionalization reactions of ketimines set the stage for the expedient synthesis of cis-beta-amino acid esters through site-and regioselective alkene annulations. The organometallic C-H activation occurred efficiently with high functional group tolerance, delivering densely functionalized beta-amino acid derivatives with ample scope
ChemInform Abstract: N‐Acyl Amino Acid Ligands for Ruthenium(II)‐Catalyzed meta‐C—H tert‐Alkylation with Removable Auxiliaries.
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