Questions tagged [reaction-mechanism]

The detailed (and as complete as possible) description of plausible or observable pathways leading from reactants to products of a chemical process. This tag should be applied to questions about these processes. It may be applied to hypothetical and/or proposed mechanisms.

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Mechanism for reaction of an allene with the Grignard Reagent(RMgX)

How does the Grignard Reagent($\ce{RMgX}$) react with an allene $\ce{CH_2=C=CH_2}$ and what are the products formed? This is exactly what I tried to do. Any help will be appreciated.
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Comparison of the rate of SN1 and SN2 reaction

It is known that $\mathrm{S_N1}$ (Substitution Nucleophilic Unimolecular) follows the order of rate of reaction: Tertiary ($3^\circ$) > Secondary ($2^\circ$) > Primary ($1^\circ$) For $\mathrm{...
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Nucleophilic Substitution rate comparison 1-bromobutane and 2-bromo-2-methylpropane with NaOH

I want to ask a question about the hydrolysis of haloalkanes to form alcohols. I have been presented with a flowchart diagram of possible reactions of haloalkanes below: Now, I have been presented ...
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Insertion vs epoxide formation

How can it be explained that in the first reaction mentioned below, a 7-membered ring dominates when the leaving group is nitrogen and an epoxide forms when the leaving group is dimethyl sulfide? This ...
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174 views

Meisenheimer complex in Preparation of 2-Naphthol from 2-Naphthalenesulfonic acid

I'm trying to figure out the addition-elimination mechanism for the preparation of 2-naphthol from 2-naphthalenesulfonic acid. I know that the $\ce{SO3^2-}$ group is functioning as the leaving group, ...
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Chemistry Behind TMOS Aerogel

I have found out how to make silica aerogel. Currently, the solution that I need to create to make the gel requires tetramethyl orthosilicate or TMOS. Furthermore, the procedure requires me to make ...
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173 views

How does the rate determining step determine the overall speed of the reaction if it is the first step in the reaction?

I can imagine it determining the rate of the whole reaction if it is the last step since that means that we will have lots of the reactants needed for the rate determining step, synthesized in earlier ...
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626 views

Dehydration: Methylcycloexanol + H2SO4 + THF

I came across this exercise: Why do we need THF? How the THF influence the mechanism? I couldn't find any link or external explanation, if you do please share. Thanks in advance.
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What is the mechanism of hydroperoxide reduction by bisulfite?

I am using bisulfite to quench allylic hydroperoxide products from a singlet oxygen ene reaction, to the corresponding alcohols. What is known about the mechanism of this reaction, and in particular ...
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104 views

Can aldol reaction occur during α-halogenation of ketone?

I know both aldol and $\alpha$-halogenation reaction well. I know that in and aldol reaction, the carbonyl containing molecules like ketones and aldehydes attacks themselves when base like $\ce{OH-}$...
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508 views

What are the products A and B in the following reaction?

What are the products A and B in the following reaction? According to me, the $\ce{NH2^-}$ anion being a strong base would form an alkoxide ion. But since there are 3 $\ce{OH}$ groups it will form ...
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What constitutes something being designated as big, bulky in terms of SN2 vs E2

When deciding between $\mathrm{S_N2}$ and $\mathrm{E2}$ for primary and secondary alkyl halides, is there a particular method or molecular size or any other threshold, which allows us to designate ...
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772 views

Iodine/ Magnesium Exchange reaction?

Traditional Grignard reagents are made by reacting alkyl halide with Magnesium metal. However, the preparation and scope of their application have been limited because of low functional group ...
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Questions about Genetic algorithm paper of Gilman and Ross

I want to reproduce an (old) biochemistry paper of Gilman and Ross, i.e. " Genetic algorithm selecetion of a regulatory structure that directs flux in a simple metabolic model." ( The following link ...
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Gilman Reagent with vinyl chloride

What are the products formed when vinyl chloride reacts with dimethyl copper? I thought the product formed would be propene. But answer given is PolyVinylChloride. How does polymerization take place?
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What reactions does this steel cold-bluing solution undergo?

Bluing steel generally refers to the process of forming a protective layer of $\ce{Fe_3O_4}$ ("black iron oxide") that prevents normal rust from forming. The chemistry behind the traditional ...
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How is the reaction between Aluminium and Mercury Chloride possible?

Aluminium is coated with a thin layer of Aluminium Oxide. Why then do we write the reaction as $$\ce{2Al + 3HgCl2 → 2AlCl3 + 3Hg}$$ Shouldn't we first write an equation showing how $\ce{HgCl2}$ ...
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Corey-Seebach reaction regioselectivity

Does Corey-Seebach reaction with conjugated enones undergo in a direct or conjugated fashion? Can the two sulfur atoms soften the carbanion enough for it to undergo conjugated addition? If not, would ...
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Does the addition of chlorine to carbon-carbon double bonds proceed through a halonium ion?

I need some serious help with the mechanism of ionic addition, both my textbook and my teacher are at odds with internet videos (khan academy) which both seem to be at odds with quote, "recent ...
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920 views

Mechanism of dehydration of alcohols by iodine/triphenylphosphine

This paper describes the dehydration of an alcohol to form an alkene. What is the mechanism of alcohol dehydration with iodine? Why can only iodine of all the halogens be used?
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947 views

Nucleophilic attack by bromine?

According this scheme the bromine act as a nucleophile and attacks pyrimidinium generating Br+ species? I always thought that Br2 acts solely as electrophile with Br- as by product.
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127 views

Iron (II) dioxygen reaction mechanism?

Ok so I'm confused about the mechanism for this process: Now the idea here is that iron first becomes oxidised to Fe(III) by placing an electron in the antibonding orbital of dioxygen. This is ...
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84 views

Grignard reaction - exchange of groups

Why is this reaction successful: Why doesn't metal-halide exchange occur easily to get Ar-MgCl and R-Br?
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Can one dichlorotriazine molecule form two bonds with cellulose?

In all the reactions I saw online, dichlorotriazine is shown to form only one bond with cellulose (example 1, example 2; paper). But cellulose has many potential sites for bonding. Can ...
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541 views

Why does the OAc group leave in the first step of Oxymercuration?

The above picture shows the first step of Oxymercuration. The electrons attack the Mercury atom but the OAc group leaves. Why is this? Hg is a transition metal with a number of available oxidation ...
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892 views

Are multiple transition states possible? Criteria to choose the correct one?

I am studying a reaction using electronic structure methods using various software packages (ORCA,GAMESS, G09) and have found two possible transition structures between product and reactant. Both have ...
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531 views

Preparing an amine from an azide

Is there any mechanism available for reduction of alkyl azides to amines. One of the reactions is conversion by $\ce{Na}$ in ethanol or by $\ce{LiAlH4}$. But how do these proceed? $\ce{LiAlH4}$ will ...
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579 views

Mechanism for conversion of imide to ester with NaH

What is the mechanism of this reaction? My proposed mechanism is shown below, would it work?
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How is elimination reaction (E1) possible without base and in presence of acid?

When learning about E1 we were taught that three things are important factors to judge if the reaction is E1 or E2 Substrate ( 3,2,1 favours E2 but only 3 favours E1 ) Base ( Stronger Base favours E2 ...
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Alternate pathway of Gabriel synthesis to prepare secondary amine

Can modifying the Gabriel synthesis, which is generally restricted to synthesis of primary amines, be used to synthesise secondary amines? I have attached my idea regarding the synthesis (the final ...
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34 views

Solvent shell collapse

In "advanced organic chemistry part A" book page:306&307 , the author uses the term 'solvent shell collapse' when talking about the reason for retention of conformation in tertiary ...
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Isomerization of phosphorylated 2-imino-1,3-dioxalanes into phosphorylated cyclic carbamates

I found a patent dating back to the Soviet Union. The patent number is 256764, and the patent describes the synthesis of phosphorylated cyclic carbamates. Here is a section of the patent, followed by ...
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Reaction of Alkyl Halide with Ag2S / Na2S

What does alkyl halides give on reaction with $\ce{Ag2S / Na2S}$? In my book, it is given as $\ce{R-S-R}$ but I am not quite sure as alkyl halide react with moist $\ce{Ag2O}$ to gives $\ce{R-OH}$ and ...
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Seeing a case where both + and - mesomeric effect is shown

I came up with that -N=O group shows both +M and -M and I understand that. In my textbook it was written that " -N=O group attached to benzene shows both + m and -m depending on the nature of other ...
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Focusing on HOMO when discussing thermal electrocyclic reactions

When taking into consideration the outcome of a thermal electrocyclic reaction, why do we focus specifically on the HOMO of the conjugated polyene? Why does it seemingly have the highest contribution ...
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55 views

Mechanism of Possible Acid Catalysed Ring Opening

Here's a problem I'm stuck with - The first step looks like the usual addition of hydroxylamine to the ketone, resulting in two diastereomeric oximes (this is probably what (A) is). Further, in the ...
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How is NaBH4 able to reduce tertiary alkyl halides to alkane but LiAlH4 create an alkene?

When attacking tertiary alkyl halides, aren't both of them just supposed to follow SN2 and substitute the leaving group with Hydride ion? Apparently only NaBH4 does it and LiAlH4 causes an E1 ...
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Reaction mechanism of lithiated benzene and oxygen in acid

According to (1) addition of O2 in acid to lithiated benzene makes phenol. I'm trying to deduce the mechanism, and somehow it doesn't feel right but I'm not sure. (1) Snieckus, V. Directed ortho ...
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Can anyone suggest a mechanism for hemiaminal metal complex to imine complex?

Can anyone suggest a probable reason for this conversion? This seems like a simple conversion from hemiaminal to imine. For secondary amine this kind of conversion might be possible by but in the ...
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102 views

How does electrophilic bromination with 1,2-dibromoethane work?

Hi I am trying to figure out the mechanism of a reaction containing a lithium carbanion and 1,2-dibromoethane in THF. The lithium carbanion is generated by deprotonating using LDA. Then 1,2-...
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Product of Diels-Alder reaction + Consecutive Reaction with base and heat

there is a problem regarding a Diels-Alder reaction that I do not understand (see image). The Diels-Alder reaction of the diene and the dienophile should lead to the product A. I hope I did it ...
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How do fuel/oxidizer combustion mechanics change when the constituents are supercritical?

The problem to solve is this: I want to create a heat generator [or heat absorber] that functions at atmospheric pressure to the pressure at the bottom of the sea. It will be used to drive a Stirling ...
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Naive question on the SN1 mechanism

I was teaching the $S_N1$ mechanism to a friend. He asked a question a subtle question I can't shake off. Take a tertiary alkyl halide and aqueous sodium hydroxide. The first step is the formation of ...
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What is the mechanism of platinum as catalyst poisons on alumina?

I'm wondering if anyone knows by what mechanism is platinum (or other noble metals) catalyst on alumina substrate poisoned? Presently, I'm using platinum on alumina to decompose a hydrogen peroxide / ...
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Emergence of Lognormal distribution for the concentration of chemical compounds

I'm currently reviewing the literature about lognormal distributions describing/approximating the variability of a given chemical compound across different cells/ samples etc etc. The main argument ...
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most frequently used organic (name) reactions

The situation: Beside the relevant inventory in the Merck index, organic-chemistry.org lists 243 name reactions (as counted on 08-Feb-2018), the compilation by Kurti and Czako includes "250 selections"...
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Kolbe's electrolysis of acetylenedicarboxylic acid

I have been wondering what this reaction would lead to? The ethyne diradical can't dimerize because triple bonded cyclic structures don't form until 8 carbons. And even if it polymerizes I find no way ...
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Please explain the reason why E2 mechanism occurs

I known as that when the weak bases are reacting with 2° alcohol, E1 mechanism occurs. But, in the picture, E2 mechanism is occurred. Why E2 mechanism occurred? In step [3] Weak base : pyridine Did ...
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How did Zyklon hold and release HCN?

$\ce{HCN}$ is notoriously unstable: It boils at room temperature, and it tends to polymerize when concentrated in unbuffered liquid form. Yet $\ce{HCN}$ was for decades widely used as a fumigant ...
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Production of oxirane mechanism

Regarding oxirane production developed by Wurtz, is there an accepted mechanism? I carried out a research but couldn't find anything. My approach was this Is that correct?

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