Questions tagged [carbocation]
Carbocations are species bearing a positive charge on carbon. They are intermediates generally formed during organic reactions, which can be stabilised by various electronic effects. Less stable carbocations are capable of undergoing rearrangements to form more stable carbocations in the course of a reaction.
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How does a carbocation have a positive charge?
When an alkene bonds with an H+ ion, the electron pair from the pi bond goes towards a new dative covalent bond with the hydrogen ion, leaving, on one side of the old double bond, a carbon bonded to ...
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Carbocation rearrangement in alkene addition reaction
This is a question from my textbook:
Determine a step-wise $S_N1$ mechanism for the overall reaction:
The solution shows the following carbocation rearrangement after Bromine leaves in the ...
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What is the reason for the exceptional stability of the cyclopropylmethyl carbocation?
Can someone explain this to me by drawing resonance structures for the cyclopropylmethyl carbocation please?
Also one more question, is the tricyclopropylmethyl carbocation more stable than tropylium ...
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Are carbocations that bad?
My professor has an anti-fetish for carbocations. In any mechanism that we draw with a carbocation, the maximum earnable credit is automatically halved. In any case, he draws all mechanisms involving ...
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The role of halogens in electrophilic aromatic substitution
I'm trying to understand what halogens do in electrophilic aromatic substitution. Consider the following.
Bromobenzene is introduced to a carbocation. Bromobenzene will likely react, but at a slower ...
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Rearrangements; Carbocations; E1 Mechanism
If the leaving of the leaving group creates a secondary carbocation, and a tertiary carbocation has the possibility of being formed through a 1,2 methyl shift:
1) Will the methyl shift? I'm guessing ...
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Migratory aptitude in pinacol-pinacolone rearrangement
I am confused about the migratory aptitude of various groups, as there are many different orders for the same given in different places, especially about -Ph and -H. I would like to know if someone ...
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Nitration of naphthalene and anthracene
In the nitration of compounds such as naphthalene and anthracene, how can you determine which would be the major product? I tried drawing resonance structures for the intermediate formed because ...
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Why are vinylic and arylic carbocations highly unstable?
I have checked the internet and read quite a few books, but I still am not able to understand why vinylic and arylic carbocations are highly unstable.
What I found while surfing the internet is: For ...
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Stability of cyclobutyl methyl carbocation
I know that cyclopropyl methyl carbocation is exceptionally stable compared to say, benzyl carbocation.
But I want to know how stable is cyclobutyl methyl carbocation compared to say, tertiary/...
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Will bridged compounds the undergo SN1 reaction?
$\mathrm{S}_{\mathrm{N}}1$ reaction involves only one molecule in the rate determining step. So, the molecule which undergoes $\mathrm{S}_{\mathrm{N}}1$ reaction should be stable when it forms a ...
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Why does carbocation stability increase in the order 1°, 2°, 3°?
I'm reading about $\:\mathrm{S_N1}$ and $\:\mathrm{S_N2}$ reaction mechanisms. 1° carbocations are unstable to the point of not having been observed in solution, ever. 2° are more stable, and 3° ...
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Resonance in carbocation derived from allenes
During a reaction if addition on one of the $\pi$ bonds of an allene (containing even number of $\pi$ bonds like $\ce {H2C=C=CH2}$) takes place then a carbocation is formed. To decide the position of ...
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Preparation of alkyl halide from alcohols
$\ce{R-OH + HBr -> R-Br + H2O}$
An $\ce{R+}$ carbocation is formed during this reaction.
If $\ce{R}$ is any alkyl group instead of methyl or ethyl, can the beta hydrogen to the hydroxy group be ...
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Why are isomers difficult to separate?
I recently learned that attempts to compare the spectra of two isomers of $\ce{C_3H_3^+}$ were frustrated by the difficulty of separating the two species.
What makes these isomers difficult to ...
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