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  2. Electrophilic aromatic directing groups - Wikipedia

    en.wikipedia.org/wiki/Electrophilic_aromatic...

    However, another effect that plays a role is the +M effect which adds electron density back into the benzene ring (thus having the opposite effect of the -I effect but by a different mechanism). This is called the mesomeric effect (hence +M) and the result for fluorine is that the +M effect approximately cancels out the -I effect.

  3. Methyl group - Wikipedia

    en.wikipedia.org/wiki/Methyl_group

    For example, protonation of methanol gives an electrophilic methylating reagent that reacts by the S N 2 pathway: CH 3 OH + H + → [CH 3 OH 2] + Similarly, methyl iodide and methyl triflate are viewed as the equivalent of the methyl cation because they readily undergo S N 2 reactions by weak nucleophiles. The methyl cation has been detected in ...

  4. Mesomeric effect - Wikipedia

    en.wikipedia.org/wiki/Mesomeric_effect

    The effect is used in a qualitative way and describes the electron withdrawing or releasing properties of substituents based on relevant resonance structures and is symbolized by the letter M. [2] The mesomeric effect is negative (–M) when the substituent is an electron-withdrawing group, and the effect is positive (+M) when the substituent ...

  5. Electrophilic aromatic substitution - Wikipedia

    en.wikipedia.org/wiki/Electrophilic_aromatic...

    Electrophilic aromatic substitution (S E Ar) is an organic reaction in which an atom that is attached to an aromatic system (usually hydrogen) is replaced by an electrophile. Some of the most important electrophilic aromatic substitutions are aromatic nitration , aromatic halogenation , aromatic sulfonation , alkylation Friedel–Crafts ...

  6. Electron-withdrawing group - Wikipedia

    en.wikipedia.org/wiki/Electron-withdrawing_group

    Electrophilic aromatic substitution is famously affected by EWGs. The effect is transmitted by inductive and resonance effects. [1] Benzene with an EWG typically undergoes electrophilic substitution at meta positions. Overall the rates are diminished. thus EWGs are called deactivating. [citation needed]

  7. Electrophile - Wikipedia

    en.wikipedia.org/wiki/Electrophile

    The electrophilic Br-Br molecule interacts with electron-rich alkene molecule to form a π-complex 1. Forming of a three-membered bromonium ion The alkene is working as an electron donor and bromine as an electrophile. The three-membered bromonium ion 2 consisted of two carbon atoms and a bromine atom forms with a release of Br −.

  8. Electrophilic substitution - Wikipedia

    en.wikipedia.org/wiki/Electrophilic_substitution

    Electrophilic substitution reactions are chemical reactions in which an electrophile displaces a functional group in a compound, which is typically, but not always, aromatic. Aromatic substitution reactions are characteristic of aromatic compounds and are common ways of introducing functional groups into benzene rings.

  9. Directed ortho metalation - Wikipedia

    en.wikipedia.org/wiki/Directed_ortho_metalation

    Directed ortho metalation (DoM) is an adaptation of electrophilic aromatic substitution in which electrophiles attach themselves exclusively to the ortho-position of a direct metalation group or DMG through the intermediary of an aryllithium compound. [1] The DMG interacts with lithium through a hetero atom.