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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]
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]
Internal alkynes feature carbon substituents on each acetylenic carbon. Symmetrical examples include diphenylacetylene and 3-hexyne. They may also be asymmetrical, such as in 2-pentyne. Terminal alkynes have the formula RC≡CH, where at least one end of the alkyne is a hydrogen atom. An example is methylacetylene (propyne using IUPAC ...
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.
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 ...
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.
Reduction of alkynes is a useful method for the stereoselective synthesis of disubstituted alkenes. If the cis -alkene is desired, hydrogenation in the presence of Lindlar's catalyst (a heterogeneous catalyst that consists of palladium deposited on calcium carbonate and treated with various forms of lead) is commonly used, though hydroboration ...