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Phenylacetylene is a prototypical terminal acetylene, undergoing many reactions expected of that functional group. It undergoes semi hydrogenation over Lindlar catalyst to give styrene . In the presence of base and copper(II) salts, it undergoes oxidative coupling to give diphenylbutadiyne . [ 6 ]
The Hay coupling is variant of the Glaser coupling. It relies on the TMEDA complex of copper(I) chloride to activate the terminal alkyne. Oxygen (air) is used in the Hay variant to oxidize catalytic amounts of Cu(I) to Cu(II) throughout the reaction, as opposed to a stoichiometric amount of Cu(II) used in the Eglington variant. [7]
An example of the Scholl reaction. Or the formation of the pyrene dibenzo-(a.1)-pyrene from the anthracene 1-phenylbenz(a)anthracene (66% yield). [8] An example of the Scholl reaction. One study showed that the reaction lends itself to cascade reactions to form more complex polycyclic aromatic hydrocarbons [9]
In organic chemistry, the Kumada coupling is a type of cross coupling reaction, useful for generating carbon–carbon bonds by the reaction of a Grignard reagent and an organic halide. The procedure uses transition metal catalysts , typically nickel or palladium, to couple a combination of two alkyl , aryl or vinyl groups .
The alkynylation reaction of aryl halides using aromatic acetylenes was reported in 1975 in three independent contributions by Cassar, [4] Dieck and Heck [5] as well as Sonogashira, Tohda and Hagihara. [6] All of the reactions employ palladium catalysts to afford the same reaction products.
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 reaction provides a means to generate alkynes from alkenes, which are first halogenated and then dehydrohalogenated. For example, phenylacetylene can be generated from styrene by bromination followed by treatment of the resulting of 1,2-dibromo-1-phenylethane with sodium amide in ammonia: [9] [10]
Menshutkin-reaction. The reaction is the method of choice for the preparation of quaternary ammonium salts. [1] Some phase transfer catalysts (PTC) can be prepared according to the Menshutkin reaction, for instance the synthesis of triethyl benzyl ammonium chloride (TEBA) from triethylamine and benzyl chloride: Menshutkin reaction