Post-polymerization modification (PPM) via direct C-H functionalization is a powerful synthetic strategy to convert polymer feed-stocks into value-added products. We found that a metal-free, Se-catalyzed allylic C-H amination provided an efficient method for PPM of polynorbornenes (PNBs) produced via ring-opening metathesis polymerization. Inherent to the mechanism of the allylic amination, PPM on PNBs preserved the alkene functional groups along the polymer backbone, while also avoiding transposition of the double bonds. Amination using a series of aryl sulfonamides led to good control over the degree of functionalization, access to a range of functionalities, and tunable thermal properties from the resulting polymers.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/anie.202303174 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Intermediate Control: Unlocking Hitherto Unknown Reactivity and Selectivity in N-Conjugated Allenes and Alkynes.
Acc Chem Res
January 2025
Department of Chemistry and Chemistry Institution for Functional Materials, Pusan National University, Busan 46241, Republic of Korea.
ConspectusControlling selectivity through manipulation of reaction intermediates remains one of the most enduring challenges in organic chemistry, providing novel solutions for selective C-C π-bond functionalization. This approach, guided by activation principles, provides an effective method for selective functional group installation, enabling direct synthesis of organic molecules that are inaccessible through conventional pathways. In particular, the selective functionalization of N-conjugated allenes and alkynes has emerged as a promising research focus, driven by advances in controlling reactive intermediates and activation strategies.
View Article and Find Full Text PDFRemote -selective C-H bromination of arenes using a recyclable Ru-based aminopropyl bifunctional PMO with robust imidazolium bridges.
Dalton Trans
January 2025
DICATECh, Politecnico di Bari, Bari, I-70125, Italy.
This systematic study delves into the synthesis and characterization of robust bi-functional aminopropyl-tagged periodic mesoporous organosilica with a high loading of small imidazolium bridges in its framework (PrNH@R-PMO-IL, ∼2 mmol g of IL). The materials proved to be a reliable and enduring support for the immobilization of Ru species, demonstrating strong performance and excellent selectivity in the -bromination of various derivatives of 2-phenylpyridine compounds and other heterocycles, showcasing its effectiveness and robust nature. The synthesized materials were thoroughly characterized to determine their structural properties, such as pore size distribution, loading of organic groups, and surface area, using various analytical techniques.
View Article and Find Full Text PDFIntegrating C-H activation/2-fold annulation: a modular access to heteroaryl-tethered oxazoloisoquinolinones.
Chem Commun (Camb)
January 2025
Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781039, India.
A cascade C-H activation/2-fold annulation of 2-aryloxazolines with pyridotriazoles has been achieved employing Rh-catalysis to afford heteroaryl-tethered oxazoloisoquinolinones. The synergistic annulations, functional group tolerance, and late-stage skeletal editing of the bioactive scaffolds are the salient practical features.
View Article and Find Full Text PDFCombined endurance and resistance exercise training in heart failure with preserved ejection fraction: a randomized controlled trial.
Nat Med
January 2025
Department for Preventive Sports Medicine and Sports Cardiology, Technical University of Munich, School of Medicine and Health, TUM University Hospital, Munich, Germany.
Endurance exercise training (ET) is an effective treatment in heart failure with preserved ejection fraction (HFpEF), but the efficacy of resistance training in this patient population has been only scarcely evaluated. In this multicenter, randomized trial, we evaluated the effects of combined endurance and resistance training over 12 months in patients with HFpEF. The primary endpoint was a modified Packer score, including all-cause mortality, hospitalizations classified as potentially related to heart failure or exercise and changes in peak oxygen consumption ( ), diastolic function (E/e'), New York Heart Association (NYHA) class and global self-assessment (GSA).
View Article and Find Full Text PDFC-C bond coupling with sp C-H bond via active intermediates from CO hydrogenation.
Nat Commun
January 2025
Key Laboratory of advanced catalysis, College of Chemistry and Chemical Engineering, Lanzhou University, 730000, Lanzhou, China.
Article Synopsis
- CO hydrogenation has been identified as a more sustainable and efficient alternative to methanol in the side-chain alkylation of 4-methylpyridine (MEPY) using a ZnZrO/CsX tandem catalyst, achieving a conversion rate of 19.6%.
- This new method results in 82% selectivity for 4-ethylpyridine (ETPY) and demonstrates 6.5 times greater activity compared to traditional methanol-mediated processes.
- The success of this catalytic process is attributed to the dual functionality of the catalyst components, facilitating both CO hydrogenation and the activation of C-H and C-C bonds, with CHO* species acting as the crucial intermediate.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!