نتایج جستجو برای: thiocarbonyl ylides

تعداد نتایج: 930  

2017

The manuscript is an update to the earlier Science of Synthesis contribution describing methods for the synthesis and new applications of thiocarbonyl S-oxides (sulfines) and thiocarbonyl S-imides. In general, thiocarbonyl S-oxides are more stable and in many instances they can be isolated in substance. The in situ generated thiocarbonyl S-imides are efficient ‘sulfur transferring agents’ via t...

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: :Chemical communications 2012
Chenjie Zhu Akira Yoshimura Pavlo Solntsev Lei Ji Yunyang Wei Victor N Nemykin Viktor V Zhdankin

Highly soluble dimedone-derived o-alkoxyphenyliodonium ylides have been prepared and characterized by single crystal X-ray diffraction. These new iodonium ylides are useful reagents for the preparation of oxazole derivatives by reaction with carbodiimides.

Journal: :journal of sciences islamic republic of iran 0

the reaction between vinylene trithiocarbonate and chlorosulfonyl isocyanate proceeds by initial attack of thiocarbonyl on the isocyanate carbon.

Journal: :The Journal of organic chemistry 2007
Stacey A Stoffregen Ryan D McCulla Robert Wilson Samuel Cercone Jennifer Miller William S Jenks

The bond dissociation enthalpies (BDEs) of sulfur and selenium ylides have been estimated by applying MP2/6-311++G(3df,2p)//MP2/6-31G(d,p), G3, and other computational methods. Computed sulfoxide bond enthalpies were compared to experimental results to ensure the reliability of the computational methods before extending to related compounds. The examined ylides include the following: sulfoxides...

Journal: :Angewandte Chemie 2007
Eiji Tayama Hiroshi Kimura

The Stevens and Sommelet–Hauser rearrangement of ammonium ylides are known as useful transformations for organic synthesis because they convert a readily accessible C–N bond into a new C–C bond. The Stevens rearrangement has been widely used for the asymmetric synthesis of α-amino acid derivatives, whereas the Sommelet–Hauser rearrangement is much less common because the Sommelet–Hauser rearran...

Journal: :Molecules 2016
Adam G Meyer John H Ryan

We provide a comprehensive account of the 1,3-dipolar cycloaddition reactions of azomethine ylides with carbonyl dipolarophiles. Many different azomethine ylides have been studied, including stabilized and non-stabilized ylides. Of the carbonyl dipolarophiles, aldehydes including formaldehyde are the most studied, although there are now examples of cycloadditions with ketones, ketenes and carbo...

Journal: :Organic & biomolecular chemistry 2011
Richard Herchl Martin Stiftinger Mario Waser

In comparison to the use of sulfur ylides, the use of ammonium ylides for the synthesis of epoxides is significantly less developed. As a part of our systematic investigations concerning the use of amide-stabilised ammonium ylides for the synthesis of glycidic amides we have focused on the identification of the best-suited amino leaving group for this purpose. Whereas tertiary amines like quinu...

2014
Natalie K. Machamer Xiaoxi Liu Stephen P. Waters

The first examples of azomethine ylides derived from allylic amine and glyoxal precursors are reported. The condensation of primary allylic and α-aryl amines with glyoxylates or α-aryl glyoxals affords conjugated azomethine ylides that undergo facile [3 + 2] cycloaddition, providing 5-alkenyl pyrrolidine cycloadducts that cannot be accessed through the classical use of amino esters as ylide pre...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید