75619-34-0Relevant articles and documents
Novel composite quaternary phosphonium salt and preparation method thereof and fluorescence application
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Paragraph 0011; 0021-0024, (2019/06/11)
The invention belongs to the technical field of functional material synthesis, and particularly relates to a novel composite quaternary phosphonium salt with fluorescence performance. The novel composite quaternary phosphonium salt is a compound composed
Untersuchungen im Wittig-System nach einem ordnenden Konzept auf der Basis alternativer Prinzipien
Bandmann, Heinz,Bartik, Tamas,Bauckloh, Sylvia,Behler, Ansgar,Brille, Frank,et al.
, p. 193 - 204 (2007/10/02)
Our results show that the stereoselectivity of the Wittig-reaction can be controlled by the variation of substituents in accord with the ORDERING CONCEPT OF ALTERNATIV PRINCIPLES (individual pairs, known and unknown classes of alternatives).The "all-phenyl Wittig-system" having three phenyl groups on phosphorous two in ylid- and aldehyd-position was chosen as a standard for our investigations.Differentiation in ylid-position and compensation on phosphorous and aldehyd-position were observed by the comparison of "patterns".Consequently, most of the selectivity rules of Wittig-reactions can be explained by the differentiation through alternatives in the ylid-position.Inversion or conservation of the "patterns" of measured data points to the variation in structure of starting materials, reaction rates and selectivities.Amount-controls were also described in certain systems.
The Chemistry of Heteroarylphosphorus Compounds, Part 14 Effects of Heteroaryl Substituents at Phosphorus on the Steric Course of Wittig Reactions of Semistabilised and Stabilised Ylides
Allen, David W.,Ward, Helen
, p. 754 - 757 (2007/10/02)
The cis-trans ratio of the stilbenes formed in Wittig reactions of semistabilised ylides (derived from benzyltri(hetero)arylphosphonium salts in ethanolic ethoxide) with benzaldehyde decreases markedly in the series 2-furyl > 2-thienyl > phenyl > 1-methylpyrrol-2-yl.The 2-furyl group favours a greater proportion of the cis-isomer than m-trifluoromethylphenyl, whereas the 1-methylpyrrol-2-yl group favours a greater proportion of the trans isomer than p-methoxyphenyl.Similarly, in Wittig reactions of carbonyl-stabilised ylides with benzaldehyde and acetaldehyde, the presence at phosphorus of 2-furyl groups results in a significant increase in the proportion of the cis-alkene compared to that formed from the related triphenylphosphonium ylide.These results are discussed in terms of both betaine and cycloaddition mechanisms for the Wittig reaction.Also discussed is their relevance to recent proposals concerning the eliminaton of alkene from the intermediate oxaphosphetan. - Keywords: Alkene cis-trans Ratio, Betaine Mechanism, Cycloaddition Mechanism