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Anti-Markovnikov behaviour extends to more chemical reactions than additions to alkenes. Anti-Markovnikov behaviour is observed in the hydration of phenylacetylene by auric catalysis, which gives acetophenone; although with a special ruthenium catalyst [8] it provides the other regioisomer 2-phenylacetaldehyde: [9] Anti-Markovnikov hydration
Hydroboration–oxidation reaction is a two-step hydration reaction that converts an alkene into an alcohol. [1] The process results in the syn addition of a hydrogen and a hydroxyl group where the double bond had been. Hydroboration–oxidation is an anti-Markovnikov reaction, with
If an epoxide mechanism is followed, hydroxide groups are added in an anti fashion. Neither Markovnikov or anti-Markovnikov because the substituents are the same. Hydrobromination: Stereospecific: Can be syn or anti addition, depending on situation. When alkenes undergo hydrobromination, the alkyl bromides are formed Markovnikov.
The net reaction is hydration. Because the addition of H-B to olefins is stereospecific, this oxidation reaction will be diastereoselective when the alkene is trisubstituted. [10] Hydroboration-oxidation is thus an excellent way of producing alcohols in a stereospecific and anti-Markovnikov fashion.
The reaction follows Markovnikov's rule (the hydroxy group will always be added to the more substituted carbon). The oxymercuration part of the reaction involves anti addition of OH group but the demercuration part of the reaction involves free radical mechanism and is not stereospecific, i.e. H and OH may be syn or anti to each other. [2] [3] [4]
Regioselectivity issues also hamper the synthetic utility of the resulting products, with Markovnikov addition of the amine being the most common outcome over the less favoured anti-Markovnikov addition (see figure). As a result, there are now numerous catalysts that can be utilised in the hydroamination of alkene, allene and alkyne substrates ...
A hydrohalogenation reaction is the electrophilic addition of hydrogen halides like hydrogen chloride or hydrogen bromide to alkenes to yield the corresponding haloalkanes. [ 1 ] [ 2 ] [ 3 ] If the two carbon atoms at the double bond are linked to a different number of hydrogen atoms, the halogen is found preferentially at the carbon with fewer ...
Hydrosilylation of alkenes usually proceeds via anti-Markovnikov addition, i.e., silicon is placed at the terminal carbon when hydrosilylating a terminal alkene; [1] however, in the recent years, Markovnikov addition has become a growing field of research. [4]