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  2. SN2 reaction - Wikipedia

    en.wikipedia.org/wiki/SN2_reaction

    Competition experiment between SN2 and E2. With ethyl bromide, the reaction product is predominantly the substitution product. As steric hindrance around the electrophilic center increases, as with isobutyl bromide, substitution is disfavored and elimination is the predominant reaction. Other factors favoring elimination are the strength of the ...

  3. Nucleophilic substitution - Wikipedia

    en.wikipedia.org/wiki/Nucleophilic_substitution

    In the intermediate step, the nucleophile is 185 degrees from the leaving group and the stereochemistry is inverted as the nucleophile bonds to make the product. Also, because the intermediate is partially bonded to the nucleophile and leaving group, there is no time for the substrate to rearrange itself: the nucleophile will bond to the same ...

  4. SNi - Wikipedia

    en.wikipedia.org/wiki/SNi

    The second step is the loss of a sulfur dioxide molecule and its replacement by the chloride, which was attached to the sulphite group. The difference between S N 1 and S N i is actually that the ion pair is not completely dissociated , and therefore no real carbocation is formed, which else would lead to a racemisation.

  5. Substitution reaction - Wikipedia

    en.wikipedia.org/wiki/Substitution_reaction

    In the first step, the leaving group departs, forming a carbocation (C +). In the second step, the nucleophilic reagent (Nuc:) attaches to the carbocation and forms a covalent sigma bond. If the substrate has a chiral carbon, this mechanism can result in either inversion of the stereochemistry or retention of configuration. Usually, both occur ...

  6. Nucleophilic aromatic substitution - Wikipedia

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

    This is because the rate-determining step for an S N Ar reaction is attack of the nucleophile and the subsequent breaking of the aromatic system; the faster process is the favourable reforming of the aromatic system after loss of the leaving group.

  7. Concerted reaction - Wikipedia

    en.wikipedia.org/wiki/Concerted_reaction

    S N 2 reaction of a bromide ion with chloroethane showing the concerted nature of the reaction, the transition state and the predictable stereochemistry through Walden inversion. In chemistry, a concerted reaction is a chemical reaction in which all bond breaking and bond making occurs in a single step.

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  9. Stereochemistry - Wikipedia

    en.wikipedia.org/wiki/Stereochemistry

    Stereochemistry, a subdiscipline of chemistry, studies the spatial arrangement of atoms that form the structure of molecules and their manipulation. [1] The study of stereochemistry focuses on the relationships between stereoisomers, which are defined as having the same molecular formula and sequence of bonded atoms (constitution) but differing in the geometric positioning of the atoms in space.