Questions tagged [nucleophilicity]
For questions involving the nucleophilicity of a chemical species. Not to be confused with "basicity", use the [acid-base] tag instead.
53
questions
-1
votes
1answer
65 views
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 ...
2
votes
1answer
32 views
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 ...
4
votes
1answer
119 views
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 ...
3
votes
0answers
32 views
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 ...
-1
votes
1answer
64 views
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
5
votes
1answer
262 views
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 ...
0
votes
0answers
41 views
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
0
votes
0answers
49 views
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 ...
2
votes
0answers
56 views
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 ...
5
votes
0answers
92 views
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 ...
0
votes
1answer
31 views
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 ...
1
vote
0answers
21 views
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 ...
7
votes
3answers
252 views
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 ...
0
votes
0answers
40 views
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 ...
6
votes
1answer
121 views
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-...
2
votes
0answers
64 views
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 ...
5
votes
0answers
67 views
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 ...
4
votes
0answers
46 views
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. ...
3
votes
0answers
38 views
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 ...
0
votes
1answer
59 views
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 $\ce{CN-};$
...
1
vote
2answers
171 views
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?
0
votes
0answers
504 views
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 ...
2
votes
0answers
123 views
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, ...
1
vote
0answers
40 views
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 ...
-1
votes
1answer
2k views
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
2
votes
0answers
946 views
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 ...
0
votes
0answers
362 views
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 ...
0
votes
0answers
46 views
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 ...
1
vote
0answers
50 views
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 ...
0
votes
1answer
2k views
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 ...
2
votes
1answer
118 views
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 ...
1
vote
1answer
439 views
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 ...
6
votes
3answers
574 views
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 ...
1
vote
0answers
108 views
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-...
1
vote
0answers
727 views
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 ...
4
votes
2answers
155 views
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
\...
0
votes
0answers
432 views
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 ...
2
votes
2answers
2k views
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 ...
4
votes
1answer
1k views
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, ...
1
vote
3answers
11k views
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 ...
0
votes
1answer
151 views
Difference in leaving group ability due to variation in nucleophiles
Wikipedia writes:
There can still exist contextual differences in leaving group ability in the purest form, that is when the actual group that leaves is not affected by the reaction conditions (by ...
1
vote
0answers
3k views
Electrophilic addition of IBr to alkene
I would assume options A and B are possible products due to the $\ce{I+}$ electrophile attacking the alkene, and hence are ruled out.
However, I am torn between options C and D. Both products are ...
1
vote
2answers
7k views
Which will give faster SN2 reaction
In $\ce{H2C=CH-Br}$ and $\ce{H3C-CH2-Br}$, which will react faster towards a $\mathrm{S_N2}$ reaction?
According to me, as double bond exhibit −I effect, hence the 1st should do a faster reaction. Am ...
1
vote
1answer
1k views
Nucleophiles in protic and aprotic solvent [closed]
If the nucleophiles have almost same size (not a large difference) such as $\ce{C- , N- , O-}$ then how their nucleophilicty varies in protic and aprotic solvents?\
Does it depend on types of ...
5
votes
0answers
2k views
Nucleophilicity of halides in solvents [duplicate]
I have studied that as electronegativity increases nucleophilicity decreases. But in the aprotic solvent the order of nucleophilicty is: $$\ce{F- > Cl- > Br- > I-}$$ but how is this possible ...
2
votes
0answers
118 views
How can a weak base act as a strong nucleophile (and vice versa)?
Carboxylate ion ($\ce{RCOO-}$) is a weak base as the negative charge on oxygen is delocalised due to resonance. So, it has less tendency to donate lone pair of electrons to H+ ion. Similarly, it has ...
16
votes
2answers
4k views
Is hydrazine a better nucleophile than ammonia?
Which is a better nucleophile, $\ce{NH3}$ or $\ce{NH2NH2}$? For the sake of limiting scope, I want an answer for behavior in a protic solvent though non-protic solvent answers are welcomed.
My logic ...
12
votes
2answers
3k views
Which is a better nucleophile: hydroxide anion or amide anion?
I know that nucleophilicity order depends on what type of solvent we take, polar protic or polar aprotic and also on the basicity of nucleophile.
In DMF, which is a better nucleophile $\ce{NH2-}$ ...
4
votes
4answers
5k views
How to determine the order of nucleophilicity for given chemical species?
How to determine the order of nucleophilicity for given chemical species?
Like I came across this question, to rearrange $\ce{RCOO-, OR-, OH-, H2O}$ (alkyl acetate, alkoxide, hydroxide, and water) in ...
2
votes
1answer
206 views
Effects of Groups on the Nucleophilcity of Nitrogen
The reactivity of nitrogen mustards increases with increasing
nucleophilicity of the central nitrogen atom. Select the most and least reactive from each of the following groups of nitrogen mustards.
...
