Publication

A new generation of "instant ylides": powder mixtures of phosphonium salts and potassium hydride as storable precursors to Wittig reagents

Manfred Schlosser
1996
Journal Articles

Abstract

Mixing a finely pulverized alkyltriphenylphosphonium salt and potassium hydride in 1:1 molar ratio gives a ready-to-use powder the components of which react rapidly when tert-Bu Me ether is added under stirring. When, in general after a few minutes, the generation of the (triphenylphosphonio)alkanide is complete, it can be immediately used for the Wittig olefination of a carbonyl compd. Compared to sodium amide based "instant ylides", the new blends offer little advantage as long as simple phosphonium salts are ingredients but they extend considerably the shelf life of mixts. contg. heterosubstituted derivs. such as methylthiomethyl- or picolyltriphenylphosphonium salts. [on SciFinder (R)]

Official source

https://infoscience.epfl.ch/entities/publication/3f338c9c-2ea4-4765-8ab6-7c5cf16afac6

About this result

This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.

Graph Chat

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

Manfred Schlosser
1996
Journal Articles

Abstract

Official source

https://infoscience.epfl.ch/entities/publication/3f338c9c-2ea4-4765-8ab6-7c5cf16afac6

About this result

Related concepts (23)

Wittig reaction

The Wittig reaction or Wittig olefination is a chemical reaction of an aldehyde or ketone with a triphenyl phosphonium ylide called a Wittig reagent. Wittig reactions are most commonly used to convert aldehydes and ketones to alkenes. Most often, the Wittig reaction is used to introduce a methylene group using methylenetriphenylphosphorane (Ph3P=CH2). Using this reagent, even a sterically hindered ketone such as camphor can be converted to its methylene derivative.

Wittig reagents

In organic chemistry, Wittig reagents are organophosphorus compounds of the formula R3P=CHR', where R is usually phenyl. They are used to convert ketones and aldehydes to alkenes: Because they typically hydrolyze and oxidize readily, Wittig reagents are prepared using air-free techniques. They are typically generated and used in situ. THF is a typical solvent. Some are sufficiently stable to be sold commercially. Wittig reagents are usually prepared from a phosphonium salt, which is in turn prepared by the quaternization of triphenylphosphine with an alkyl halide.

Phosphonium

In chemistry, the term phosphonium (more obscurely: phosphinium) describes polyatomic cations with the chemical formula PR4+ (where R is a hydrogen or an alkyl, aryl, or halide group). These cations have tetrahedral structures. The salts are generally colorless or take the color of the anions. The parent phosphonium is PH4+ as found in the iodide salt, phosphonium iodide.