A novel PNN-type pincer ligand has been accessed via imine reduction with LiAlH to provide the phosphine diamino proligand, PNN (1). The ligand, 1, as well as PNP can be metallated directly, via N-H cleavage, with LReOX(OEt) precursors to access six-coordinate (PNP)ReOCl (2) and (PNN)ReOX (3-Cl, X = Cl; 3-Br, X = Br) in good yield. 3-Cl and 3-Br undergo dehydrohalogenation upon treatment with NEt, furnishing the five-coordinate phosphine/diamido PNN-type compounds (PNN)ReOX (4-Cl, X = Cl; 4-Br, X = Br) in excellent yield, presenting as a mixture of rotameric diasteromers. The reversibility of this deprotonation, and the coordinative unsaturation of 4-Cl is shown in reactions with HCl and PMe providing 3-Cl and 4-PMe3, respectively. Treatment of 4-Cl with AgOAc, AgOTf, or NaHBEt lead to formation of (PNN)ReO(OAc) (4-OAc), (PNN)ReO(OTf) (4-OTf), and (PNN)ReO(H) (4-H), all isolated in excellent yields in varying diasteromeric ratios. The nature of the isomerism was analyzed based on solid-state structural studies and solution NMR data.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1039/c6dt03640f | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Full conversion of lignocellulose using polyoxometalate catalysts with redox sites and antagonistic acidity/basicity.
J Colloid Interface Sci
November 2024
Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education, Faculty of Chemistry, Northeast Normal University, Changchun 130024, PR China. Electronic address:
The full utilization of lignocellulose involves two distinct catalytic routes: i) oxidative depolymerization of lignin and ii) acid/alkaline hydrolysis of hemicellulose and cellulose. To improve efficiency and reduce costs, constructing a single-cluster catalyst represents a desirable yet challenging strategy. Herein, triple-functional molecular polyoxometalates (POMs), NLLHVMoO (n = 1-6) were fabricated using N-lauroyl-l-lysine (NLL) and HVMoO as precursors.
View Article and Find Full Text PDFSelective [3 + 2] C-H/C-H Alkyne Annulation via Dual (Distal) C-H Bond Activation Relay: A Novel Therapeutic Quinazolone-Tethered Benzofulvenes for Oral Cancer.
JACS Au
November 2024
Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER) - Ahmedabad, Palaj, Gandhinagar 382355, Gujarat, India.
Article Synopsis
- The text discusses a new method for activating distal C-H bonds to create benzofulvenes, which are compounds formed through a [3 + 2] reaction involving palladium catalysis, overcoming traditional bond activation challenges.
- This innovative approach involves concurrent activation of both β-C(benzylic)-H and δ-C(aryl)-H bonds and leads to the formation of novel chemical entities with promising anticancer properties.
- In studies, these new compounds were found to effectively target oral squamous cell carcinoma (OSCC) by arresting the cell cycle at the S-phase and activating various apoptosis pathways, indicating their potential as effective chemotherapy options.
N-H Bond Activation of Ammonia by a Redox-Active Carboranyl Diphosphine.
J Am Chem Soc
December 2024
Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter St., Columbia, South Carolina 29208, United States.
Article Synopsis
- This study presents a new method for activating the N-H bond in ammonia at room temperature using a specific diphosphine compound, leading to a zwitterionic product.
- Unlike traditional phosphorus-based methods that require structural constraints, this process relies on the teamwork of electron-rich phosphine centers and an electron-accepting carborane cluster.
- The research highlights a unique, metal-free approach to ammonia oxidation through triple hydrogen atom abstraction, demonstrating that activation can occur in the presence of air and water without the need for metal catalysts.
Comparative study between UVB 313 nm, UVC 254 nm, and far UVC 222 nm light on the aging of polyamide 66.
Heliyon
October 2024
Centro de Investigaciones y de Estudios Avanzados Del I.P.N. Unidad Querétaro, Querétaro, Querétaro, C.P. 76230, Mexico.
Polyamide-66 underwent substantial growth worldwide in the late 1930's. It can be found in several public spaces. After 2019, due to the coronavirus disease (COVID-19), the sanitization of the interior of aircraft and public spaces by using UV light became important.
View Article and Find Full Text PDFIsatoic anhydride as a masked directing group and internal oxidant for Rh(III)-catalyzed decarbonylative annulation through C-H activation: insights from DFT calculations.
Chem Commun (Camb)
October 2024
College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, China.
Density functional theory calculations uncovered a new mechanism for the rhodium-catalyzed decarbonylative annulation of isatoic anhydride with alkynes, in which the acyloxy group formed from the N-H deprotonation and C-O bond cleavage of isatoic anhydride acts as the directing group to assist the C-H activation. From the generated five-membered rhodacycle intermediate, the final aminoisocoumarin product could be formed by subsequent steps of alkyne insertion, reductive elimination, decarbonylation, and protonation. The isocyanate moiety contained in the annulation intermediate was uncovered as a novel internal oxidant for the reaction, which oxidizes the Rh(I) to Rh(III) by decarbonylation.
View Article and Find Full Text PDFWant 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!