Formaldehyde is a VOC gas that plays a key role in air pollution. To limit emissions into the environment, the utilization of this waste as a raw material is a promising way. In this work, the M06-L functional calculation was used to investigate the structure, electronic properties, and catalytic activity of group IIA metals (Be, Mg, and Ca) partial substitution on Cu-BTC paddlewheels for formaldehyde encapsulation and carbonyl-ene reaction with propylene. Formaldehyde is absorbed by the metal center of the paddlewheel via its oxygen atom. The adsorption of formaldehyde on the substituted metal sites increased as compared to the parent Cu-BTC which can facilitate formaldehyde to react with propylene. The adsorption free energies are predicted to be -15.1 (Be-Cu-BTC), -14.7 (Mg-Cu-BTC), and -14.5 (Ca-Cu-BTC) kcal mol, respectively. The substituted metal has a slight effect on the Lewis acidity of the Cu ion in the paddlewheel. The adsorption free energy of formaldehyde, similar to that found in the pristine Cu-BTC, is observed. For the carbonyl-ene reaction, the reaction is proposed via a single step involving the C-C bond formation between two reactants and one hydrogen of propylene methyl group moves to formaldehyde oxygen, simultaneously. It was found that the substituted metals do not affect the catalytic performance of the Cu center for this reaction. The activation energies for the reaction at the Cu center are in the range of 22.0-23.4 kcal mol, which are slightly different from Cu-BTC (21.5 kcal mol). Interestingly, the catalytic activity of this reaction on the substituted metal is greater than that on the Cu center. The catalytic activities are in the order Be-Cu-BTC (13.3 kcal mol) > Mg-Cu-BTC (15.9 kcal mol) > Ca-Cu-BTC (17.8 kcal mol). Among them, the Be site of the bimetallic Be-Cu-BTC paddlewheel is predicted as a promising candidate catalyst.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.jmgm.2024.108756 | DOI Listing |
RSC Adv
October 2024
Instituto de Tecnología Química (UPV-CSIC), Universidad Politècnica de València-Agencia Estatal Consejo Superior de Investigaciones Científicas Avda. de los Naranjos s/n 46022 Valencia Spain
The intermolecular carbonyl-ene reaction of ketones is still considered a challenge in organic chemistry, particularly with reusable solid catalysts, and implemented in a domino reaction. Herein, we show that the extremely cheap and non-toxic solid salt MgCl catalyzes the reaction of trifluoromethyl pyruvates not only during the conventional carbonyl-ene reaction with various aromatic and alkyl alkenes (in very high yields, up to >99%) but also in a domino reaction with the corresponding alcohols (precursors to the alkenes) in similar good yields. The solid can be reused in both cases without any erosion of the catalytic activity and can be employed in an in-flow process to maximize the reaction throughput.
View Article and Find Full Text PDFOrg Lett
May 2024
Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States.
We report an experimental and computational investigation of the likely mechanism of a cascade reaction. The reaction involves an intramolecular Diels-Alder reaction, followed by a C-C bond cleavage, to afford a complex bridged bicyclic product. As multiple reaction pathways could be envisioned for the latter step, the mechanism of the C-C bond cleavage step was investigated.
View Article and Find Full Text PDFJ Mol Graph Model
June 2024
Center for Advanced Studies in Nanotechnology for Chemical, Food, and Agricultural Industries, Kasetsart University Institute for Advanced Studies, Kasetsart University, Bangkok, 10900, Thailand; Department of Chemistry, Faculty of Science, Kasetsart University, Bangkok, 10900, Thailand. Electronic address:
Formaldehyde is a VOC gas that plays a key role in air pollution. To limit emissions into the environment, the utilization of this waste as a raw material is a promising way. In this work, the M06-L functional calculation was used to investigate the structure, electronic properties, and catalytic activity of group IIA metals (Be, Mg, and Ca) partial substitution on Cu-BTC paddlewheels for formaldehyde encapsulation and carbonyl-ene reaction with propylene.
View Article and Find Full Text PDFOrg Lett
September 2023
Department of Chemistry, The University of Adelaide, Adelaide, SA 5005, Australia.
Hyperireflexolides A and B were synthesized in six steps via the dearomatization and fragmentation of a simple acylphloroglucinol starting material. The dearomatized acylphloroglucinol undergoes a sequence of oxidative radical cyclization, retro-Dieckmann fragmentation, stereodivergent intramolecular carbonyl-ene reactions, and final α-hydroxy-β-diketone rearrangements to give the target natural products. This sequence is based on a biosynthetic proposal that claims the hyperireflexolides as highly rearranged polycyclic polyprenylated acylphloroglucinols (PPAPs), which is supported by the structural revision of hyperireflexolide B.
View Article and Find Full Text PDFChem Sci
August 2023
Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University Chengdu 610064 P. R. China
A bimetallic tandem catalysis-enabled enantioselective cycloisomerization/carbonyl-ene reaction was developed. The reaction proceeded well with a broad range of -propargylamides and acylsilanes, affording the target chiral 5-oxazoylmethyl α-silyl alcohols in up to 95% yield and 99% ee under mild conditions. Importantly, this facile protocol was available for the late-stage modification of several bioactive molecules.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!