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  2. SN2 reaction - Wikipedia

    en.wikipedia.org/wiki/SN2_reaction

    Elimination reactions are usually favoured at elevated temperatures [15] because of increased entropy. This effect can be demonstrated in the gas-phase reaction between a phenolate and a simple alkyl bromide taking place inside a mass spectrometer: [16] [17] Competition experiment between SN2 and E2

  3. Nucleophilic substitution - Wikipedia

    en.wikipedia.org/wiki/Nucleophilic_substitution

    The two main mechanisms were the S N 1 reaction and the S N 2 reaction, where S stands for substitution, N stands for nucleophilic, and the number represents the kinetic order of the reaction. [4] In the S N 2 reaction, the addition of the nucleophile and the elimination of leaving group take place simultaneously (i.e. a concerted reaction).

  4. SN1 reaction - Wikipedia

    en.wikipedia.org/wiki/SN1_reaction

    If the reaction is performed under warm or hot conditions (which favor an increase in entropy), E1 elimination is likely to predominate, leading to formation of an alkene. At lower temperatures, S N 1 and E1 reactions are competitive reactions and it becomes difficult to favor one over the other. Even if the reaction is performed cold, some ...

  5. Nucleophilic aromatic substitution - Wikipedia

    en.wikipedia.org/wiki/Nucleophilic_aromatic...

    This reaction differs from a common S N 2 reaction, because it happens at a trigonal carbon atom (sp 2 hybridization). The mechanism of S N 2 reaction does not occur due to steric hindrance of the benzene ring. In order to attack the C atom, the nucleophile must approach in line with the C-LG (leaving group) bond from the back, where the ...

  6. Substitution reaction - Wikipedia

    en.wikipedia.org/wiki/Substitution_reaction

    Substitution reactions in organic chemistry are classified either as electrophilic or nucleophilic depending upon the reagent involved, whether a reactive intermediate involved in the reaction is a carbocation, a carbanion or a free radical, and whether the substrate is aliphatic or aromatic. Detailed understanding of a reaction type helps to ...

  7. SNi - Wikipedia

    en.wikipedia.org/wiki/SNi

    With standard S N 1 reaction conditions the reaction outcome is retention via a competing S N i mechanism and not racemization and with pyridine added the result is again inversion. [5] [3] S N i reaction mechanism Sn1 occurs in tertiary carbon while Sn2 occurs in primary carbon

  8. Dissociative substitution - Wikipedia

    en.wikipedia.org/wiki/Dissociative_substitution

    Dissociative pathways are characterized by a rate determining step that involves release of a ligand from the coordination sphere of the metal undergoing substitution. The concentration of the substituting nucleophile has no influence on this rate, and an intermediate of reduced coordination number can be detected.

  9. Williamson ether synthesis - Wikipedia

    en.wikipedia.org/wiki/Williamson_ether_synthesis

    In order for the S N 2 reaction to take place there must be a good leaving group which is strongly electronegative, commonly a halide. [4] In the Williamson ether reaction there is an alkoxide ion (RO −) which acts as the nucleophile, attacking the electrophilic carbon with the leaving group, which in most cases is an alkyl tosylate or an ...