نتایج جستجو برای: phosphine ylide

تعداد نتایج: 3902  

2014
Victor K. Outlaw Craig A. Townsend

Among privileged structures, indoles occupy a central place in medicinal chemistry and alkaloid research. Here we report a flexible and efficient conversion of pyrrole-3-carboxaldehydes to substituted 7-amino-5-cyanoindoles. Phosphine addition to fumaronitrile proceeds with prototropic rearrangement of the initially formed zwitterion to the thermodynamically favored phosphonium ylide, which is ...

Journal: :Chemical communications 2015
Peter A Byrne Yannick Ortin Declan G Gilheany

P-Hydroxytetraorganophosphorane, the long-postulated intermediate in phosphonium salt and ylide hydrolysis, has been observed and characterised by low temperature NMR, finally definitively establishing its involvement in these reactions. The results require modification of the previously accepted mechanism for ylide hydrolysis: P-hydroxytetraorganophosphorane is generated directly by 4-centre r...

Journal: :Angewandte Chemie 2021

Secondary ligand–metal interactions are decisive in many catalytic transformations. While arene–gold have repeatedly been reported as critical structural feature high-performance gold catalysts, we herein report that these can also be replaced by Au???H?C hydrogen bonds without suffering any reduction performance. Systematic experimental and computational studies on a series of ylide-substitute...

Journal: :The Journal of organic chemistry 2009
William S Jenks Melanie J Heying Stacey A Stoffregen Erin M Rockafellow

Photolysis of derivatives of dimethylmalonate thiophene-S,C-ylide provides dicarbomethoxycarbene, which can react with thiophene to form dimethyl (2-thienyl)malonate. By generation of dicarbomethoxycarbene from the dibenzothiophene-based ylide in neat thiophene, it is shown that the thienylmalonate is not a product of rearrangement of the thiophene ylide, in contrast to thermolysis results. For...

Journal: :Journal of the American Chemical Society 2010
Samantha L Riches Chandreyee Saha Noelia Fontán Filgueira Emma Grange Eoghan M McGarrigle Varinder K Aggarwal

In this paper, we describe studies on the cyclopropanation of Michael acceptors with chiral sulfur ylides. It had previously been found that semi-stabilized sulfonium ylides (e.g., Ph-stabilized) reacted with cyclic and acyclic enones and substituted acrylates with high ee and that stabilized sulfonium ylides (e.g., ester-stabilized) reacted with cyclic enones again with high ee. The current st...

Journal: :Organometallics 2022

Thanks to the +PCy3 substituents which are unlikely undergo intramolecular C–H activation, Pd(II) complex [(C,C,C)PdCl](OTf) having a neutral LX2-type NHC, diphosphonium bis(ylide) pincer ligand was selectively prepared by double deprotonation of [(NHC)PdCl2(Py)] precursor with tBuOK. The influence on overall electronic properties this scaffold evaluated IR spectroscopy data corresponding Pd–CO...

Journal: :Organic & biomolecular chemistry 2014
Christina T Lollar Katherine M Krenek Kevin J Bruemmer Alexander R Lippert

An exceptionally mild method for the preparation of isatin derivatives has been developed using a sulfur ylide mediated carbonyl homologation sequence starting from anthranilic acid precursors. This method proceeds at ambient temperature via a sulfur ylide intermediate without the need for protection of the amine or chromatographic isolation of the intermediate ylide. Gentle oxidation of the su...

Journal: :Molecules 2012
Keisuke Gondo Tsugio Kitamura

Reaction of dibenzoylmethane with (diacetoxyiodo)benzene in the presence of KOH in MeCN quantitatively gave the corresponding iodonium ylide, which was treated with a HF reagent to afford the corresponding 2-fluorinated dibenzoylmethane in 14-50% yields. The similar reaction of the iodonium ylides obtained from 1-phenylbutan-1,3-dione, ethyl benzoylacetate, and ethyl p-nitrobenzoylacetate with ...

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