Questions tagged [nucleophilicity]
For questions involving the nucleophilicity of a chemical species. Not to be confused with "basicity", use the [acid-base] tag instead.
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Why can't ethoxide ion act as nucleophile?
Consider the reaction of chlorocyclohexane with ethoxide in a suitable inert solvent. The major product according to my textbook is cyclohexene, which implies E2 reaction pathway. Why not SN2?
$\ce{...
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Effect of Solvent - Nucleophilicity of RS- and RO-
While reading on order of nucleophilicity of $\ce{RS-}$ and $\ce{RO-}$, I came across this:
Source: Page 355, Organic Chemistry by Jonathan Clayden, Nick Greeves, and Stuart Warren
However, my teacher ...
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Iodide ion is good leaving group and a good nucleophile. How can both be correct?
Leaving Group Tendency of Iodide
$\ce{I-}$ size is big.
$\ce{I-}$ has stable negative charge.
$\implies$ $\ce{I-}$ is good leaving group.
Nucleophilicity of Iodide
$\ce{I-}$ size is big.
$\ce{I-}$...
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What determines strength of nucleophile--Polarisability or Electron density
My understanding is that nucleophiles are lewis bases. Apparently nucleophile and base strength are not the same though. I thought Nu strength/Base strength is determined by how well it can donate an ...
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In hydroboration oxidation reaction .. why do not we use sodium hydroxide alone as a nuclophile?
Why do not we use sodium hydroxide alone as a nuclophile instead of using hydrogen peroxide along with sodium hydroxide
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Why is the reaction rate of tert-butyl chloride solvolysis faster in 80% water/20% acetone, than in 70% water/30% acetone?
The solvent is polar protic, so the mechanism is SN1. However, I don't understand how the composition of water and acetone in the solvent affects the reaction rate.
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Why are cyanamides more electrophilic than nitriles?
According to https://www.researchgate.net/publication/6642597_A_generally_applicable_method_for_assessing_the_electrophilicity_and_reactivity_of_diverse_nitrile-containing_compounds, cyanamides (...
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Can alkyl halides react with guanidine/guanidino groups?
I wonder how the π delocalization of guanidino groups affects the reactivity of the terminal nitrogens with respect to alkyl halides compared to, say, primary amines?
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How is propene more reactive as well as more stable than ethene?
I know that hyperconjugation stabilises a double bond. But in propene an electron-donating group $(\ce{-CH3})$ is increasing the electron density at the double bond, so its nucleophilicity should be ...
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What is the product when alcohol is added to carbonyl compounds? [closed]
How do we know if, on adding alcohol to carbonyl compound:
nucleophilic addition reaction will take place
or
alcohol will take alpha hydrogen to form a carbanion and consequent
aldol condensation ...
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Stereochemical outcomes for hydrohalogenation when there is a carbocation rearrangement
The following reaction is given:
I want to be able to tell which of the following stereochemical outcomes are possible.
I am aware that there are other possible products than the ones shown here ...
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Comparing Rate of Hydrolysis of Acyl halides
In this particular question, my answer is (D) as steric hinderance is minimum there, but answer (B) was given due to the electron withdrawing (-M) effect of the nitro group.
Isn't steric hinderance ...
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Selectivity in tosylation of sulphur and oxygen
Problem
Answer
Question
The first step involves a nucleophilic substitution on the sulphur atom of the tosyl group. I reasoned that in the cyclohexane substrate, the sulphur atom (thiol group) will ...
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Who makes a better nucleophile? CH3O- or OH-? [duplicate]
My argument is that the +I effect of CH3 group increases the electron density at oxygen atom, making it a better nucleophile
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Possible dehydration after nucleophilic addition
Here is the question:
My reasoning was the following:
The ethoxide ion first abstracts a proton from the $\mathrm{sp^3}$ carbon of the cycloalkene. This carbon then attacks the electrophilic carbonyl ...
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Which double bond will PhMgBr attack and why? [duplicate]
I am confused about which double bond will undergo nucleophilic addition.C=O should undergo but the book says the double bond of the ring.Please tell why
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Which oxygen in ester group is more nucleophilic?
According to my understanding, the filled orbital (lone pair electron for this) is more nucleophilic (higher energy) if:
it has more $\mathrm p$ character (since p orbital is the furthest from the ...
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Difference between nucleophilicity of phenoxide ion and acetate anion in protic/aprotic solvent
As far as I could think, the phenoxide ion is comparatively larger as compared to acetate ion, so it should undergo less solvation in presence of a protic solvent and thus its nucleophilicty should be ...
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Which is better leaving group out of iodide and water?
In hydrolysis reaction of an tertiary alkyl halide , $\ce{H_2O}$ will replace the $\ce{I-}$ through $\ce{S_N1}$ mechanism and then $\ce{H+}$ will be removed from $\ce{H_2O}$ in order to form an ...
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Do ambident nucleophiles form functional isomers?
I came across cyanide and isocyanide in an example for functional isomerism. As they are also ambident nuclephiles, I wanted to know if other ambident nucleophiles would also exhibit functional ...
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Confusion regarding nucleophilicity [duplicate]
My teacher told me that to compare nucleophilicity, check the size of the attacking atom. Bigger the attacking atom more the nucleophilicity. But while reading Solomon, I found out that the order of ...
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Comparing the rates of hydrolysis of different haloalkanes
The title may not completely explain my exact doubt so I'll explain it here:
My teacher gave me the following problem during a lecture about SN1 reactions and I had to determine the order of the rate ...
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Comparing nucleophilic strengths of tetrahydropyran and (2R,6R)-2,6 dimethyltetrahydropyran
Compare the nucleophilic strengths of the following two compounds:
According to me it should be the second one, that is, (2R,6R)-2,6-dimethyltetrahydropyran because the methyl groups would exert +I ...
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Will "soft nucleophiles" undergo 1,4-conjugate addition even if the β-carbon is sterically hindered?
In general soft nucleophiles do 1,4 conjugate addition to a carbonyl carbon under thermodynamic control. Will soft nucleophiles like organocuprates still preferentially undergo 1,4 addition if the β-...
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Are solvent effects the reason for the methoxide ion to be a stronger nucleophile than the thiomethoxide ion?
Between $\ce{CH3O-}$ and $\ce{NC-}$, $\ce{NC-}$ is a better nucleophile than $\ce{CH3O-}$ in a polar protic solvent, while $\ce{CH3O-}$ is a better one in a polar aprotic solvent, because in a polar ...
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Orbital Interaction for electrophile and nucleophile
Clearly, the above diagrams depict the interaction between empty orbital of electrophile with filled orbital of nucleophile. We may assume that the HOMO of nucleophile being more electronegative will ...
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Why are Grignard reagents nucleophiles and not ambiphiles?
The way I see it, the -R (alkyl part) obtains a negative charge and the MgX obtains a net positive charge on bond dissociation. So a nucleophile and an electrophile both are obtained simultaneously. ...
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Reactivity of unsaturated organolithium compounds
I'm particularly looking in the context of alkyl lithiums compared to vinyl-lithiums and alkynyl-lithiums.
Why is it that shifting from sp3 to sp2, and even further to sp carbanions, reduces the ...
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SN2 on compound containing halogen and carbonyl
I was given the following question on a sample exam for my organic chemistry course:
I am quite certain that it would happen in a SN2-type reaction considering that
the nucleophile is $\ce{CN-};$
...
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When does Alcohol act as Solvent and as a Nucleophile?
I was recently solving problems related to Alcohol.
and its solution is
My doubt is why methanol act as a nucleophile here and when does alcohol acts as a nucleophile and as a Solvent?
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Order of nucleophilicity of ammonia, hydrazine and hydroxylamine
I was reading about nucleophilicity and basic strength orders. I came across this interesting set of three compounds $\ce{NH3},$ $\ce{N2H4}$ and $\ce{NH2OH}$ where I am not able to apply the rules I ...
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Why basicity decreases for leaving groups, but nucleophicity increases for an overall compound, going down the periodic table?
Basically, I read that nucleophilicity increases going down the periodic table within a particular group, due to polarizability, but basicity decreases down a group (or family) in the periodic table, ...
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Synthesis of Schiff Bases in Aqueous Media
The paper https://www.hindawi.com/journals/jchem/2013/909217/ describes a possibility to synthesize salicylaldehyde-based Schiff Bases using water as a solvent. Yields shown for the microwave-assisted ...
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Which one is the stronger nucleophile? CH3CH2O or CH3CO2 [closed]
Not really sure what the principle would be. Maybe it has something to do with the resonance capability of the two Os in CH3CO2
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Which is a stronger nucleophile in aprotic solvent: water or hydrogen sulfide? [duplicate]
Which one is the stronger nucleophile in aprotic solvent: $\ce{H2O}$ or $\ce{H2S}?$
According to my notes, nucleophilicity order is directly proportional to basicity order in an aprotic medium, and ...
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Order of nucleophilicity of Nitrogen atoms in adenine
I recently stumbled upon a question that got me thinking. It goes something like this:
Find the major product of the following reaction:
There were 3 options given:
So it basically aims at finding ...
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Reactivity of carbonyl derivatives with a nucleophile [duplicate]
As observed, the reactivity of carbonyl derivatives with a nucleophile goes like:
Acid halide > acid anhydride > acid > amide > ketone > aldehyde. So is nucleophile a code word to nucleophilic ...
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Source of highly nucleophilic iodide [closed]
What is be the best commercially available source of highly nucleophilic iodide in non-polar solvent? Solvents used are cyclohexane, benzene, chlorobenzene.
I can get ahold of bromide quaternary ...
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Why is N- a better nucleophile than S-?
I can't rationalize why S- is a worse nucleophile than N-. I thought nucelophilicity was related to electronegativity, the more electronegative an atom is, the less of a nucleophile it is. Sulfur is ...
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Why polar aprotic solvents don't surround negatively charged nucleophiles?
Protic solvents can form a tight shell around a nucleophile. But what's stopping any polar solvent from doing so? Shouldn't a polar solvent surround negatively charged $\ce{F-}$ with its partially ...
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Bromination of an alkene in presence of water
Bromination of an alkene in presence of water results in its mechanism in a cyclic bromonium ion and "afterwards $\ce{H2O}$ binds to the carbon atom surrounded by more electron donating groups."
This ...
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Nucleophilicity in polar aprotic solvent (DMSO)
The strength of a nucleophile in polar aprotic solvent is proportional to its basicity. Lone pair on O- in the molecules will donate an e- pair to an atom. I'm not sure why the alkene ring in 2 makes ...
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Reactivity towards nucleophillic addition
Phenyl ethanal or ethanal
I thought phenyl methanal is less reactive towards nucleophilic attack due to presence of bulky group. But answer in my book suggest ethanal is less reactive.
Para-...
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Nucleophilicity and basicity of compounds with or without nitrogen inversion
In nitrogen inversion, the lone pair changes its direction continuously.
Does this in any way delocalize the charge density on the nitrogen making it less nucleophilic and less basic than, say, a ...
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Nucleophilicity methanol vs water [closed]
I have a short question: Which among Methanol and water will be a better nucleophile for a reaction carried out in some polar protic solvent .
Searching over the internet suggests that methoxide ion ...
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Nucleophilic nature of ions
Consider the following species:
$$
\underset{(\text{A})}{\ce{\overset{⊖}{O}H}}
\quad
\underset{(\text{B})}{\ce{CH3-\overset{⊖}{O}}}
\quad
\underset{(\text{C})}{\ce{\overset{⊖}{C}H3}}
\quad
\...
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Nucleophilic addition - Propanal vs Benzaldehyde
According to my school textbook, carbon atom of the carbonyl group benzaldehyde is less electrophilic than that of propanal because polarity of the carbonyl group is reduced in benzaldehyde due to ...
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Order of Nucleophilicity
I know this question has been asked many times but I need to confirm this doubt which has been pestering me for the past few days.
Suppose in an $\mathrm{S_N2}$ reaction (in polar aprotic solvent) we ...
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Why is fluoride the most nucleophilic halide in aprotic solvents? [duplicate]
I am confused on the topic of electronegative nucleophiles, and polar aprotic solvents.
From my understanding, the more electronegative a nucleophile is, the weaker of a nucleophile it will be, ...
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Why does using NaI as a nucleophile and acetone as solvent lead to an SN2 reaction mechanism instead of SN1? Is I- not considered a weak nucleophile?
In a reaction with a secondary leaving group, why does using $\ce{NaI}$ with acetone as a solvent lead to an $\mathrm{S_N2}$ reaction mechanism instead of $\mathrm{S_N1}$? I thought that halogens were ...
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