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An electrophile reacts in the next phase in an electrophilic aromatic substitution with a strong preference for the lithium ipso position replacing the lithium atom. Ordinary electrophilic substitutions with an activating group show preference for both the ortho and para position, this reaction demonstrates increased regioselectivity because ...
This reaction is similar to nucleophilic aliphatic substitution where the reactant is a nucleophile rather than an electrophile. The four possible electrophilic aliphatic substitution reaction mechanisms are S E 1, S E 2(front), S E 2(back) and S E i (Substitution Electrophilic), which are also similar to the nucleophile counterparts S N 1 and ...
The Schiff base is an electrophile which reacts in a second step in an electrophilic addition with an enol formed from a carbonyl compound containing an acidic alpha-proton. The Mannich reaction is a condensation reaction. [4]: 140 In the Mannich reaction, primary or secondary amines or ammonia react with formaldehyde to form a Schiff base ...
This reaction occurs in a similar way to the addition reaction but has an extra step in which the OSO 3 H group is replaced by an OH group, forming an alcohol: C 2 H 4 + H 2 O → C 2 H 5 OH. As can be seen, the H 2 SO 4 does take part in the overall reaction, however it remains unchanged so is classified as a catalyst. This is the reaction in ...
Since then, a number of studies have firmly established the mechanism of electrophilic attack on vinyl- and allylsilanes [4] [5] The electron-releasing strength of the carbon-silicon bond is large, and as a result, the position of silicon in the unsaturated silane controls the site of reaction and stereoselectivity. Formation of the new carbon ...
Sulfur trioxide or its protonated derivative is the actual electrophile in this electrophilic aromatic substitution. To drive the equilibrium, dehydrating agents such as thionyl chloride can be added: [2] C 6 H 6 + H 2 SO 4 + SOCl 2 → C 6 H 5 SO 3 H + SO 2 + 2 HCl. Historically, mercurous sulfate has been used to catalyze the reaction. [3]
The reaction mechanism for this reaction is depicted in scheme 5. The carbonyl reactant (2) is protonated by a protic acid and for the resulting oxonium ion 3 two resonance structures can be drawn. This electrophile engages in an electrophilic addition with the alkene to the carbocationic intermediate 4.
In organic chemistry, an electrophilic addition (A E) reaction is an addition reaction where a chemical compound containing a double or triple bond has a π bond broken, with the formation of two new σ bonds. [1] The driving force for this reaction is the formation of an electrophile X + that forms a covalent bond with an electron-rich ...