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Safe and scalable synthesis of alkynes from aldehydes. Recently a safer and more scalable approach has been developed for the synthesis of alkynes from aldehydes. This protocol takes advantage of a stable sulfonyl azide, rather than tosyl azide, for the in situ generation of the Ohira−Bestmann reagent. [6]
An alkyne trimerisation is a [2+2+2] cycloaddition reaction in which three alkyne units (C≡C) react to form a benzene ring. The reaction requires a metal catalyst. The process is of historic interest as well as being applicable to organic synthesis. [1] Being a cycloaddition reaction, it has high atom economy.
The second step of the reaction to convert dibromoolefins to alkynes is known as Fritsch–Buttenberg–Wiechell rearrangement. The overall combined transformation of an aldehyde to an alkyne by this method is named after its developers, American chemists Elias James Corey and Philip L. Fuchs. The Corey–Fuchs reaction
Transition metal alkyne complexes are often formed by the displacement of labile ligands by the alkyne. For example, a variety of cobalt-alkyne complexes arise by the reaction of alkynes with dicobalt octacarbonyl. [2] Co 2 (CO) 8 + R 2 C 2 → (R 2 C 2)Co 2 (CO) 6 + 2 CO. Many alkyne complexes are produced by reduction of metal halides: [3]
The Crabbé reaction (or Crabbé allene synthesis, Crabbé–Ma allene synthesis) is an organic reaction that converts a terminal alkyne and aldehyde (or, sometimes, a ketone) into an allene in the presence of a soft Lewis acid catalyst (or stoichiometric promoter) and secondary amine.
This concept has been applied to methods for the synthesis of organic compounds from alkenyl- and alkynylalanes. The most notable applications are methods for the stereospecific synthesis of olefins. Alkenylalanes, which are easily synthesized with complete stereocontrol through alkyne hydroalumination, transfer the alkenyl unit to a variety of ...
Click chemistry is an approach to chemical synthesis that emphasizes efficiency, simplicity, selectivity, and modularity in chemical processes used to join molecular building blocks. It includes both the development and use of "click reactions", a set of simple, biocompatible chemical reactions that meet specific criteria like high yield, fast ...
Grignard reagents of acetylene or alkynes can be used to perform alkynylations on compounds that are liable to polymerization reactions via enolate intermediates. However, substituting lithium for sodium or potassium acetylides accomplishes similar results, often giving this route little advantage over the conventional reaction.