نتایج جستجو برای: ene reaction
تعداد نتایج: 416165 فیلتر نتایج به سال:
This study sought to assess the prognostic significance of the degree of extranodal extension (ENE) and several other risk factors in pathological ENE penile carcinoma. We analyzed prospectively collected data on a consecutive series of 31 chemotherapy-naive patients with proven ENE who underwent therapeutic regional lymphadenectomy. Postoperative external radiotherapy was then performed. We st...
In this research, dried acetone:chloroform extract of aerial parts of E. denticulata as one of the endemic plants to Iran, afforded a number of triterpenes and steroids including: betulin, 24-methylene-cycloart-3-ol, cycloart-23Z-ene-3β,25-diol, cycloart-23Z-ene-3β,25-diol, ergosta-8,24-dien-3-ol (obtusifoliol) and beta-sitosterol which were reported for the first time from this plant. The stru...
Fractionation of a steam distilled residue of Commiphora confusa resin has yielded four novel dammarane triterpenes characterised as (20S)-3beta-acetoxy-12beta,16beta-trihydroxydammar-24-ene, (20S)-12beta,16beta-trihydroxydammar-24-ene-3beta-O-beta-glucopyranoside, (20S)-3beta-acetoxy-12beta,16beta,25-tetrahydroxydammar-23-ene, and (20S)-3beta,12beta,16beta,25-pentahydroxydammar-23-ene. The kno...
The dried plant was extracted with dichloromethane and after defatting with hexane, transferred repeatedly on silica columns using dichloromethane-hexane and ethyl acetate-hexane as mobile phases. Finally the fractions were purified by high performance liquid chromatography using a Pack-Sil column and hexane: Ethyl acetate as mobile phase. The structures of the isolated compounds included: cycl...
The dried plant was extracted with dichloromethane and after defatting with hexane, transferred repeatedly on silica columns using dichloromethane-hexane and ethyl acetate-hexane as mobile phases. Finally the fractions were purified by high performance liquid chromatography using a Pack-Sil column and hexane: Ethyl acetate as mobile phase. The structures of the isolated compounds included: cycl...
Radical-mediated thiol-yne step-growth photopolymerizations are utilized to form highly cross-linked polymer networks. This reaction mechanism is shown to be analogous to the thiol-ene photopolymerization; however, each alkyne functional group is capable of consecutive reaction with two thiol functional groups. The thiol-yne reaction involves the sequential propagation of a thiyl radical with e...
The mechanism of the polar reaction between the superelectrophile PTAD (2) and diene (6b) in the presence of THF has theoretically been studied at the MPWB1K/6-311G** level. Our investigations reveal that this reaction takes place through a stepwise mechanism via formation of intermediate (7b) with a strong zwitterionic character. The first step of the reaction, which is associated with the nuc...
Two new ruthenium complexes with chelating-ether benzylidene ligands bearing a furan moiety were synthesized and characterized, including X-ray crystallography. They initiated fast, also at 0 °C, found to be highly active in variety of ring-closing, ene-yne, cross-metathesis reactions, an pharmaceutical ingredient (API) model, which makes them good candidates for the transformation complex poly...
Straightforward access to [1,2]-annulated indoles, key substructures in natural products, is highly desirable yet challenging. Herein, a radical triggered fragmentary cyclization cascade reaction of ene-ynamides presented, providing rapid into indoles by an intermolecular addition, intramolecular cyclization, desulfonylative aryl migration, and site-selective C(sp2)-N sequence. DFT calculations...
Exo- and endocyclic double bonds of glycals and terminal double bonds of enoses were reacted with various thiols by irradiation with UV light in the presence of a cleavable photoinitiator. The photoinduced radical-mediated hydrothiolation reactions showed highly varying overall conversions depending not only on the substitution pattern and electron-density of the double bond but also on the nat...
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