61892-85-1Relevant academic research and scientific papers
A modified synthesis of (Z)-pyrethrolone
Markham, Todd E.,Duggan, Peter J.,Johnston, Martin R.
, p. 99 - 109 (2022/03/16)
An accessible, efficient, and reliable synthesis for the production of (Z)-pyrethrolone remains necessary as previous syntheses suffer from drawbacks including the use of toxic reagents, expensive starting materials and lack of regioselectivity in the production of key intermediates. This work attempts to alleviate the issues of prior syntheses by making use of well-known and regioselective transformations for the efficient synthesis of (Z)-pyrethrolone. Ultimately, (Z)-pyrethrolone is generated in an overall 20% yield over five steps from a cheap, easily accessible starting material using reliable, optimised transformations.
Cyclopentadienyl-Ru(II)-Pyridylamine Complexes: Synthesis, X-ray Structure, and Application in Catalytic Transformation of Bio-Derived Furans to Levulinic Acid and Diketones in Water
Dwivedi, Ambikesh D.,Sahu, Vinod K.,Mobin, Shaikh M.,Singh, Sanjay K.
, p. 4777 - 4787 (2018/04/25)
A series of cationic half-sandwich cyclopentadienyl-ruthenium(II)-pyridylamine complexes, [(η5-C5H5)Ru(κ2-L)(PPh3)]+ (L = Namine-substituted pyridylamine ligands) ([Ru]-1-[Ru]-6), along with the analogous cyclopentadienyl-ruthenium(II)-N-isopropylpyridylimine complex [(η5-C5H5)Ru(κ2-L)(PPh3)]+ (L = N-isopropylpyridylimine) ([Ru]-7), have been synthesized in good yields. Structural identities of all the complexes have been authenticated by 1H, 13C, and 31P NMR, mass spectrometry, and X-ray crystallography. The synthesized complexes exhibited high catalytic activity for the transformation of the bio-derived furans, 2-furfural (furfural), 5-methyl-2-furfural (5-MF), and 5-hydroxymethyl-2-furfural (5-HMF) to levulinic acid (LA) and the diketones, 3-hydroxyhexane-2,5-dione (3-HHD), 1-hydroxyhexane-2,5-dione (1-HHD), and hexane-2,5-dione (HD) in water. Efficient transformation of furfural to LA over a range of η5-Cp-Ru-pyridylamine complexes is substantially affected by the Namine-substituents, where a η5-Cp-Ru-N-propylpyridylamine complex ([Ru]-2) exhibited higher catalytic activity in comparison to other η5-Cp-Ru-pyridylamine and η5-Cp-Ru-pyridylimine complexes. The relative catalytic activity of the studied complexes demonstrated a substantial structure-activity relationship which is governed by the basicity of Namine, steric hindrance at Namine, and the hemilabile nature of the coordinated pyridylamine ligands.
Ruthenium and Formic Acid Based Tandem Catalytic Transformation of Bioderived Furans to Levulinic Acid and Diketones in Water
Dwivedi, Ambikesh D.,Gupta, Kavita,Tyagi, Deepika,Rai, Rohit K.,Mobin, Shaikh M.,Singh, Sanjay K.
, p. 4050 - 4058 (2015/12/26)
Efficient tandem catalytic transformations of bioderived furans, such as furfural, 5-hydroxymethylfurfural (5-HMF), and 5-methylfurfural (5-MF), to levulinic acid (LA) and diketones, 1-hydroxyhexane-2,5-dione (1-HHD), 3-hydroxyhexane-2,5-dione (3-HHD), and hexane-2,5-dione (2,5-HD), was achieved by using water-soluble arene-RuII complexes, containing ethylenediamine-based ligands, as catalysts in the presence of formic acid. The catalytic conversion of furans depends on the catalyst, ligand, formic acid concentration, reaction temperature, and time. Experimental evidence, including time-resolved 1H NMR spectral studies, indicate that the catalytic reaction proceeds first with formyl hydrogenation followed by hydrolytic ring opening of furans. The ruthenium-formic acid tandem catalytic transformation of fructose to diketones and LA was also achieved. Finally, the molecular structures of the four representative arene-RuII catalysts were established by single-crystal X-ray diffraction studies.
Catalytic transformation of bio-derived furans to valuable ketoacids and diketones by water-soluble ruthenium catalysts
Gupta, Kavita,Tyagi, Deepika,Dwivedi, Ambikesh D.,Mobin, Shaikh M.,Singh, Sanjay K.
supporting information, p. 4618 - 4627 (2015/09/15)
Bio-derived furans such as 2-furfural (furfural), 5-hydroxymethyl-2-furfural (5-HMF) and 5-methyl-2-furfural (5-MF) were successfully transformed to a ketoacid, levulinic acid (LA), and diketones, 1-hydroxyhexane-2,5-dione (1-HHD), 3-hydroxyhexane-2,5-dione (3-HHD) and hexane-2,5-dione (HD), under moderate reaction conditions using water soluble and recyclable 8-aminoquinoline coordinated arene-ruthenium(ii) complexes. Under the optimized reaction conditions using 1 mol% catalyst in the presence of 12 equivalents of formic acid at 80-100 °C, complete conversion of furfural to LA with high selectivity was achieved. Several experiments along with 1H NMR spectral studies are described which provide more insights into the mechanism underlying the transformation of furans to open ring components. Experiments performed using structural analogues of the active catalyst inferred a structure-activity relationship for the observed superior catalytic activity of the 8-aminoquinoline coordinated arene-ruthenium(ii) complex. Furthermore, due to the high aqueous solubility of the studied complexes, high recyclability, up to 4 catalytic runs, was achieved without any significant loss of activity. Molecular identities of the studied 8-aminoquinoline coordinated arene-ruthenium(ii) complex were also confirmed using single-crystal X-ray diffraction studies.
Silyl Nitronates in Organic Synthesis. Routes to Heterocycles and Cyclopentanoids. Synthesis of Allethrolone and Calythrone. Acylation and Cyanohydroxylation of Double Bonds. An Exploratory Study
Andersen, Soeren H.,Das, Nalin B.,Joergensen, Ruth D.,Kjeldsen, Gunhild,Knudsen, Jes S.,et al.
, p. 1 - 14 (2007/10/02)
Silyl nitronates are versatile reagents for the preparation of heterocycles by dipolar addition to double bonds.The intermediate isoxazolidines can be transformed to 2-isoxazolines, isoxazoles, furans, dihydrofuranones, pyrazoles, pyridazines and pyridazones.Reduction of 2-isoxazolines with Ti3+ leads to hydroxylated 1,4-diketones, which subsequently can be cyclized to cyclopentenones.Routes to calythrone, rethrolones, prostanoids and a number of naturally occurring dihydrofuranones are devised, as well as synthetic procedures for acylation, preparation of endiones, hydroxyacylation, cyanation and hydroxycyanation of double bonds.
