A Lewis acid catalyzed [3+4]-annulation reaction between cyclopropane 1,1-diesters and anthranils has been developed. This annulation consists of a reaction sequence involving ring-opening/aromatization/nucleophilic addition. Thereinto, aromatization is the driving force for this annulation. Using this reaction, a series of 8-oxa-1-azabicyclo[3.2.1]octanes can be prepared conveniently with excellent diastereoselectivity.
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http://dx.doi.org/10.1039/c7cc04239f | DOI Listing |
J Org Chem
January 2025
Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
The selective oxidative cleavage and functionalization of C(OH)-C bonds in tertiary alcohols harbor immense feasibility in organic synthesis and enable the production of high value-added chemicals from renewable biomass. However, it remains a challenge, owing to the inherent kinetic inertness and thermodynamic stability of C(OH)-C bonds and the lack of C-H. Taking the huge potential and challenge of C(OH)-C bond activation and functionalization into consideration, herein, we show the first example of an inexpensive bifunctional ferric nitrate catalyst for catalytic direct oxidation of structurally distinct tertiary alcohols to esters with environmentally benign molecular oxygen as an oxidant and MeOH as a solvent, without the assistance of any additives.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
State Key Laboratory of Green Chemical Engineering and Industrial Catalysis, Research Institute of Industrial Catalysis, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
Catalytic elimination through an oxidative decomposition pathway is the most promising candidate for the purification of chlorinated volatile organic compound (CVOC) pollutants, but the complicated mechanisms and the formation pathways of hydrogenated byproducts still need to be clearly revealed. Herein, W/ZrO, as a structure-tunable catalyst, is used to catalytically oxidize dichloromethane (DCM) and clarify the formation pathway of monochloromethane (MCM). Crystal engineering of ZrO tailors surface WO species; practically, the predominant Zr-WO clusters and crystalline WO can be obtained on monoclinic (m-ZrO) and tetragonal (t-ZrO) phases.
View Article and Find Full Text PDFOrg Lett
January 2025
State Key Laboratory of Antiviral Drugs, Pingyuan Laboratory, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China.
Highly asymmetric (3+3) annulation of diaziridines with oxiranes via C-N bond cleavage in diaziridine was achieved under 10 mol % of chiral copper(II) complex as the catalyst under mild reaction conditions. With Cu(OTf) as the Lewis acid and C-symmetric imidazolidine-pyrroloimidazolone pyridine as the ligand, diverse tetrahydro-[1,3,4]-oxadiazines were obtained by stereospecific C-N/C-O bond formation in moderate to good yields (up to 93% yield) and high diastereo- (>20:1 dr) and enantioselectivities (up to 92% ee). The catalytic cycle and stereochemical model were proposed by DFT calculation.
View Article and Find Full Text PDFJ Org Chem
January 2025
Chemical Sciences and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram 695019, India.
We have developed efficacious routes toward the selective synthesis of two classes of compounds such as C-3 amino-methylated indoles and 4-indol-3-yl-methylanilines from the same precursors, namely, indoles and 1,3,5-triazinanes. It is reported that the controlled cleavage of 1,3,5-triazinanes can be effected by heat for the generation of aryl imine motifs, and we observed that the presence of Lewis acid influences the course of these transformations toward different products. The reaction toward indol-3-yl-methylanilines proceeds via a nucleophilic attack of indole to the aryl imine generated from the 1,3,5-triazinanes to form an amino-methylated product which undergoes a Lewis acid mediated Hofmann-Martius-type rearrangement.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Institut für Chemie, Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129, Oldenburg, Germany.
The iodination of electron-deficient arenes and heteroarenes is a long-standing problem in organic synthesis. Herein we describe the electrochemical iodination in nitromethane with BuNI as iodine source and supporting electrolyte under Lewis acid-free conditions in the presence of small amounts of chloride anions. The electrochemically generated reagent could be applied for the iodination of halogenated arenes, aromatic aldehydes, acids, esters, ketones, as well as nitroarenes to afford the products in good to excellent yields.
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