90072-83-6Relevant academic research and scientific papers
Laccase-catalyzed stereoselective oxidative ring opening of 2,5-dialkylfurans into 2-ene-1,4-diones using air as an oxidant
Asta, Chimene,Conrad, Juergen,Mika, Sabine,Beifuss, Uwe
, p. 3066 - 3069 (2011/12/21)
The laccase-catalyzed ring opening of 2,5-dimethylfuran using air as an oxidant stereoselectively yields (Z)- or (E)-3-hexene-2,5-dione depending on the mediator employed: with TEMPO the (Z)-3-hexene-2,5-dione is formed, while a combination of TEMPO and violuric acid gives (E)-3-hexene-2,5-dione. The (Z)-selective ring cleavage was extended to a variety of symmetrical and unsymmetrical 2,5-dialkylfurans. The Royal Society of Chemistry.
Functionalised cis-Alkenes from the Stereoselective Decomposition of Diazo Compounds, Catalysed by [RuCl(η5-C5H5)(PPh3)2]
Zotto, Alessandro Del,Baratta, Walter,Verardo, Giancarlo,Rigo, Pierluigi
, p. 2795 - 2802 (2007/10/03)
A catalytic amount of [RuCl(η5-C5H5)(PPh3)2] (1) (0.1 mol- percent) at 60 deg C stereoselectively decomposes α-diazo carbonyl compounds N2CHCOR [R=EtO, Me, Et, nPr, iPr, Ph, (CH2)10Me, and (CH2)14Me] affording quantitatively RCOCH=CHCOR carbene dimers [R=EtO (10), Me (11), Et (12), nPr (13), iPr (14), Ph (15), (CH2)10Me (16), and (CH2)14Me (17)]. The cis isomer is formed in 95-99 percent purity, depending on the R group. Under the same experimental conditions, N2CHCOR1 and N2CHCOR2 react in equimolar amounts to give mixtures of unsymmetrical cis-R1COCH=CHCOR2 (18-32), and symmetrical cis-R1COCH=CHCOR1 and cis-R2COCH=CHCOR2 alkenes. The unsymmetrical cis-alkenes 23-32 are formed in about 50 percent yield from the reaction between two α-diazo ketones. The yield of the cis-R1COCH=CHCOR2 compounds 18-22 increases to ca. 60 percent when a mixture of α-diazo ketone and N2CHCOOEt is catalytically decomposed. Higher conversions into the unsymmetrical products have been obtained by treating N2CHCOR and N2CHSiMe3, from which cis-RCOCH=CHSiMe3 derivatives 34-41 are formed in 83-91 percent yield. The catalytic decomposition of α,ω-bis(diazo) ketones N2CHCO(CH2)nCOCHN2 (n=4, 8, or 10) has also been investigated, and found to afford cyclic cis-alkenes arising from both intra- [n=4 (45), 8 (46), and 10 (47)] and intermolecular carbene-carbene coupling processes.
Oxidations catalysed by rhenium(V) oxo species 1. Conversion of furans to enediones using methyltrioxorhenium and urea hydrogen peroxide
Finlay, James,McKervey, M. Anthony,Gunaratne, H. Q. Nimal
, p. 5651 - 5654 (2007/10/03)
Methyltrioxorhenium is an efficient catalyst for the oxidative ring opening of several substituted furans to enediones using urea hydrogen peroxide.
Oxidation of β,γ-unsaturated ketones with molecular oxygen catalyzed by metal phthalocyanines and porphyrins: A pratical synthesis of oxophorone
Ito, Nobuhiko,Etoh, Takeaki,Hagiwara, Hisahiro,Kato, Michiharu
, p. 153 - 155 (2007/10/03)
Oxidation of 3,5,5-trimethylcyclohex-3-en-1-one (1) with molecular oxygen catalyzed by metal phthalocyanines (Pc) and 5,10,15,20-tetraphenylporphyrins (TPP) including Mn(II), Mn(III), Fe(II), Fe(III), Co(II), Cu(II), and Ru(II) to 3,5,5-trimethylcyclohex-2-ene-1,4-dione (2) was studied. TPPMn(III)Cl showed an excellent catalytic activity, affording 2 in 93percent yield and 12500 turnover number.
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.
