Questions tagged [nucleophilicity]
For questions involving the nucleophilicity of a chemical species. Not to be confused with "basicity", use the [acid-base] tag instead.
37
questions
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1answer
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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 $\ce{CN-};$
...
2
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2answers
99 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?
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0answers
178 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 ...
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0answers
61 views
Can someone clarify this rationale for using polar, protic solvents in an Sn1?
In the textbook I am reading, it states that an Sn1 mechanism prefers a (polar) protic solvent because the protic solvent helps stabilize the carbocation and solvate the kleavin group, facilitating ...
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0answers
35 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, ...
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0answers
16 views
I'm so confused about the ranking of nucleophilicity please help me!
My instinct is the third one with a minus charge must have biggest nucleophilicity. The second is bigger than first one since lower electronegativity. I guess frist one is less nucleophile than last ...
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0answers
37 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
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1answer
735 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
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49 views
Nucleophilicity order of charged and uncharged nucleophile in polar protic solvent
I have read that in polar protic solvents, greater the charge density of a nucleophile, weaker is the nucleophile because of solvent effects. Thus iodide ion is better nulceophile than bromide, ...
2
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0answers
50 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 ...
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0answers
197 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 ...
1
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0answers
40 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
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0answers
39 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
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1answer
798 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
81 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 ...
0
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1answer
219 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
269 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 ...
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0answers
83 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-...
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0answers
427 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
104 views
Nucleophilic nature of ions
Consider the following species:
$$
\underset{(\text{A})}{\ce{\overset{ā}{O}H}}
\quad
\underset{(\text{B})}{\ce{CH3-\overset{ā}{O}}}
\quad
\underset{(\text{C})}{\ce{\overset{ā}{C}H3}}
\quad
\...
0
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0answers
330 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
1k 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
825 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
6k 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
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1answer
112 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 ...
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0answers
2k 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
4k 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 āI effect, hence the 1st should do a faster reaction. Am ...
1
vote
1answer
991 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 ...
4
votes
0answers
1k 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
69 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 ...
14
votes
2answers
3k 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 ...
10
votes
2answers
2k 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 $\ce{NH2-}$ ...
3
votes
4answers
4k 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
176 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.
...
4
votes
2answers
5k views
Ranking order of nucleophilicity
According to me the answer should be (c),(b),(a),(d). As we move left to right in a period the electronegativity increases and hence the tendency to donate electrons will decrease so nitrogen is ...
13
votes
2answers
1k views
Nucleophilicity with respect to the solvent
I am currently studying nucleophilicity of molecules and am getting a set of conflicting information, so I wanted to clarify nucleophilicity trends with respect to solvent.
Master Organic Chemistry ...
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3answers
32k views
How to determine order of nucleophilicity among commonly used nucleophiles?
How to determine order of nucleophilicity among commonly used nucleophiles? For example, in Finklestein reaction, $\ce{NaI}$ (reagent) - taken in acetone (solvent) - displaces $\ce{SH-}$ ion from ...
