نتایج جستجو برای: wittig reaction
تعداد نتایج: 412686 فیلتر نتایج به سال:
An efficient three-component reaction of dialkyl acetylendicarboxylates and 2-Pyrrolidin in the presence of triphenylphosphine produces dialkyl 2-(2-Pyrrolidin-N-yl)-3-(triphenylphosphanylidene)succinate. These phosphoranes undergo mild intramolecular Wittig reaction to produce dialkyl (E)-2-(4,5-dihydro-3H-pyrrol-2-yl)fumarate in excellent yields.
Key words (–)-peyssonnoside A - diterpene glycoside marine natural product antimicrobial dearomative cyclization HAT-initiated Wittig reaction Mukaiyama hydration
Stilbene and phenylethynylstilbene units are excellent candidates for fluorescent sensor synthesis. In this paper we show a fast efficient method the preparation of fluorophores based on biphenyl nuclei with phenylene-vinylene functionalized by donor groups. Using pallado catalysed coupling reactions Sonogashira types Wittig or Wittig-Horner reaction, stilbene phenylethylsilbene arms O-alkyl N-...
Reaction of ethyl (Z)-3-(heteroaryl/aryl)-2-((triphenyl-λ5-phosphaneylidene) amino) acrylates intermediates with 2,3-thiophenedicarboxaldehyde was used in novel Tandem three consecutive reactions: aza-Wittig, imine condensation and electrophilic heteroaromatic cyclization to obtain a series indolizines. A tentative mechanism this reaction is proposed.
The cis-trans ratio of the alkenes formed in Wittig reactions of semistabilised ylides (derived from benzyltriarylphosphonium salts in ethanolic sodium ethoxide) with benzaldehyde, acetaldehyde or trimethylacetaldehyde increases as steric crowding at phosphorus increases. In contrast, the cis-trans ratio of the unsaturated esters formed in the related reactions of the stabilised ethoxycarbonylm...
General. All reactions were performed under argon using Schlenk techniques. Diethyl ether and THF were freshly distilled from sodium/benzophenone prior to use. 1 H, 13 C and 31 P spectra were recorded on a 400 MHz and 300 MHz spectrometers. Chemical shifts (ppm) were reported and referenced to the internal signal of residual protic solvent. High resolution mass spectral analyses (HRMS) were per...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید