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30 Νοε 2012 · For our purposes, “ strong ” nucleophiles/bases are negatively charged and “ weak” nucleophiles/bases are neutral. A good rule of thumb is to expect SN2/E2 with “ strong ‘ (i.e. negatively charged) nucleophiles/bases and expect SN1/E1 with neutral nucleophiles/bases.
- The Solvent
I heard the explanation is that OH- is a good nucleophile...
- The Solvent
In the term S N 2, S stands for 'substitution', the subscript N stands for 'nucleophilic', and the number 2 refers to the fact that this is a bimolecular reaction: the overall rate depends on a step in which two separate molecules (the nucleophile and the electrophile) collide. The mechanism starts when lone pair electrons from the nucleophile ...
23 Ιαν 2023 · The O of - OH is a better nucleophile than the O of H 2 O, and results in a faster reaction rate. Similarly, when nitrogen is part of NH 2, it bears a negative charge, and when it is part of NH 3, it is neutral. The N of NH 2 is a better nucleophile than the N of NH 3, and results in a faster reaction rate.
4 Δεκ 2012 · I heard the explanation is that OH- is a good nucleophile for an SN2 reaction, and when there’s alcohol and KOH the OH- can deprotonate the alcohol to get alkoxide ion, which is a stronger base than a nucleophile, so takes a proton for an E2 reaction.
24 Μαΐ 2021 · Strength of the Nucleophile (Nucleophilicity) In the SN2 reaction, the rate determining step for the reaction is the attack of the nucleophileto the substrate. Therefore, SN2 is easier to perform for stronger nucleophiles. There are predictable periodic trends in nucleophilicity.
15 Μαρ 2018 · Some general guidelines for understanding S N 2 reactions include: (a) stronger bases are better nucleophiles, unless an E2 pathway is accessible which benefits more from a strong base than S N 2; (b) leaving groups with a weak bond to the substrate present enhanced reactivity (C−I C−F); (c) increasingly electropositive central atoms result ...
31 Αυγ 2020 · A Lewis base acting as a strong nucleophile is needed for S N 2 reactions, whereas a Lewis base acting as a strong protophile (i.e., base) is required for E2 reactions. A complicating factor is, however, the fact that a good nucleophile is often a strong protophile.
