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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Do Cyclohexane-1,3-diones Give Positive Haloform Reactions?

Recently a post appeared on ChemSE asking why cyclohexane-1,3-dione (dihydroresorcinol) 1a doesn’t give a positive iodoform test. Unfortunately, the post was subsequently taken down after several ...
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Reaction of SeCl4 with alkene and possible consecutive reaction?

There is a reaction that confused me a bit: According to my research on $\ce{SeCl4}$, it can be used as a dichlorinating agent for alkenes. However, I am totally confused about the mechanism. I've ...
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Synthesis of Anthracene: Mechanism

Recently, I happened to find a problem that involved the synthesis of anthracene from bromobenzene in the presence of tert-butyl lithium, using THF as the solvent, and at room temperature. I am ...
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Mechanism for an Étard reaction (chromium complex)

In the following reaction, a chromium complex is formed during the Étard reaction: I have the following questions: How is this complex formed? How does its hydrolysis take place? (What's the ...
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Can I make Ferrofluid without evaporating Ammonium?

I want to make ferrofluid, which is ferromagnetic particles suspended in a carrier fluid. Three methods I have seen involve using magnetic ink (for MICR codes), cassette tapes, or ferric chloride as ...
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Why does adipic acid give a cyclic ketone on heating while glutaric acid and succinic acid give a cyclic anhydride?

Why does adipic acid give cyclic ketone on heating while glutaric and succinic acid give cyclic anhydride?
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Grubbs, Wittig & hydroboration reactions and Woodward-Hoffmann rules

Several organic mechanisms I know involve [2+2] cycloadditions and retro-[2+2] cycloadditions, namely: The Wittig reaction Hydroboration of an alkene Olefin metathesis (using Grubbs' catalyst) How ...
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Oxidation of naphthalene with KMnO4

What is the product when naphthalene is oxidized by alkaline (or acidic) solutions of $\ce{KMnO4}$? Some possible reactions show up in a google search, but they have no references: Naphthalene to ...
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Can we use PI3 in HVZ reaction?

With the help of HVZ reaction, we can get alpha-chloro or alpha-bromo carboxylic acid. But can we make alpha-iodocarboxylic acid with the help of HVZ reaction? I could not find any reference of HVZ ...
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Solve this chemical or biological mystery

I hope this is the best place to pose this unique question. Please forgive me if it's not. I went into a closet to get a prescription medication that was filled about a year ago. The label on the ...
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Mechanism for Ce(IV) Oxidation of Naphthalene

S. Cotton's Lanthanide and Actinide Chemistry reports that naphthalene can be oxidized to naphthalene-1,4-dione using cerric ammonium sulfate (CAS), $\ce{MeCN, H2SO4},$ and $\ce{H2O}$.1 No mechanism ...
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Why does the presence of EWG's on the aryldiazonium ring increase the yield of a Meerwein arylation?

In my textbook, Strategic Applications of Named Reactions in Organic Synthesis, the author says the following regarding properties of the Meerwein arylation: The general features of this reaction ...
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Finding theoretical mechanism of sodium thiosulphate and hydrochloric acid

In class we conducted an experiment where we timed reactions between sodium thiosulphate and hydrochloric acid. We kept the concentration of the $\ce{HCl}$ constant, while changing the concentrations ...
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Treatment of ketones with excess Tebbe reagent

The reaction in black below was presented in a set of lecture notes as an example of the use of the Tebbe reagent, however it's not immediately obvious (to me, at least) that the product should be the ...
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821 views

Mechanism for the decomposition of HI

I've been trying to find the mechanism for the gas phase decomposition of hydrogen iodide: $$\ce{ 2 HI (g) <=> H2 (g) + I2 (g)} $$ Anyone know of sources where I can get information on this? I ...
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What is the degradation mechanism of pyrrole?

A vial of pyrrole (that was occasionally exposed to air) changed its color while degrading from pale yellow to dark orange. What is the mechanism of pyrrole degradation? What are the resulting ...
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328 views

Lemieux-Johnson oxidation on cycles

Consider 5-cyano-2,2-dimethylpentyl 4-methylbenzene-1-sulfonate: What would it yield by a Lemieux-Johonson oxydation ($\ce{OsO4}$, $\ce{NaIO4}$)? My first guess would have been that $\ce{OsO4}$ was ...
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Is there a bifurcation node in the potential energy as a function of reaction progress equation of chemical reactions?

I originally posted a similar question on math.stackexchange.com, but I believe I might have a better chance of having my question answered here after giving it some time. I was thinking about the ...
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Orientation in benzene rings with more than one substituent

Why is it that the chlorination of 1-chloro-3-nitrobenzene (18) gives 1,4-dichloro-2-nitrobenzene (19) as the major product, 1,2-dichloro-3-nitrobenzene (20) as a minor product and 1,2-dichloro-4-...
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Why transition metal catalyzed [2+2]cycloaddition reactions allowed?

As you know, cycloaddition reactions which (4n)π electrons are involved in such as [2+2]cycloaddition are forbidden in normal organic reactions, but transition metal catalyzed [2+2]cycloaddition ...
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What drives the 'internal return' in SNi?

I just learnt that alcohols can undergo $\mathrm{S_N}i$ with $\ce{SOCl2}$ (without pyridine) to achieve retention: However, what I really do not understand is the 'internal return' step (forming '...
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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 $\mathrm{S_N2}$ and substitute the leaving group with Hydride ion? Apparently only $\ce{NaBH4}$ does it and $\ce{...
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791 views

Reaction of cyclopropane with hot potassium permanganate

Hot potassium permanganate is usually used as an oxidising agent, and cyclopropane being an unstable three membered ring undergoes reaction with several reagents such as bromine, $\ce{HBr}$, metal ...
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143 views

How to account for the interface between two different phases in a discretized diffusion model?

I have tried to set up a model for the diffusion of a gas into a liquid. The two media are next to each other and the geometry is spherical because the system should simulate the diffusion out of a ...
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146 views

Which site is more favorable for EAS in O-Acetotoluidide?

Which site is more favorable for electrophilic aromatic substitution in O-Acetotoluidide? The answer given in my textbook says the site para to acetamide group is more favorable, however I believe ...
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How to theoretically predict thermodynamic stability?

Let's say we have $\ce{CH3-NH2}$ undergoing Hoffman's exhaustive methylation with $\ce{CH3-Cl}$. In which case side reactions such as $\ce{CH3-NH2 + CH3-NH2 -> CH3NHCH3 + NH3}$ would also occur. ...
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381 views

Compounds that Liberate Hydrogen from Water, Reversibly

I'm working on a paper which provides an overview of all the current methods for storing hydrogen gas as part of a renewable energy system, and I understand compressed gas and metal hydride storage ...
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Why does reduction of naphthalene with nickel/hydrogen lead to trans-decalin?

Is there any reason why $\ce{H2/Ni}$ leads to trans-decalin? I knew from high school that catalytic hydrogenations are always syn.
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Side chain formation in polymerisation of ethylene

I am having difficulty understanding (or at least need confirmation of my understanding) of this diagram regarding the formation of sidechains of polyethylene. If someone could explain it, that would ...
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Mechanism of toluene oxidation with CrO3

What is the mechanism for the following oxidation of toluene with $\ce{CrO3}$ in acetic anhydride? Use of chromic oxide ($\ce{CrO3}$): Toluene or substituted toluene is converted to benzylidene ...
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Asymmetric Suzuki coupling - saturated alkyl chain

9-BBN is applied for Suzuki coupling of a saturated alkyl chain with some alkenyl,alkynyl or even secondary alkyl halide like the modification attached: (Saito, B.; Fu, G. C. Alkyl−Alkyl Suzuki Cross-...
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Why do NaNO3 + Al + NaOH yield ammonia?

From Russian test problem 4301: $$\ce{3NaNO3 + 8Al + 5NaOH + 18H2O -> 8Na[Al(OH)4] + 3NH3(g)}$$ How does ammonia evolve here? Is it that we get hydrogen gas evolving in the reaction between Al ...
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Formose reaction - mechanism of first step

The following image was taken from wikkipedia's article about the Formose reaction. What is the mechanism of the first step of the reaction sequence? How do the two formaldehyde molecules condense?
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Mechanism of reaction between substituted aniline and potassium thiocyanate in presence of bromine and glacial acetic acid

Im currently doing this project where in we are synthesizing 2-amino-6-substituted benzothiazole by using p-substituted aniline with potassium thiocyanate in presence of bromine and glacial acetic ...
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What prevents self-condensation in the Perkin reaction?

An acid anhydride is condensed with an aromatic aldehyde in the Perkin reaction. The latter is non-enolisable, and thus the former forms the enolate which attacks as a nucleophile. If the attack is ...
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How does the Kucherov reaction work if the alkyne is aromatic?

I know how the Kucherov reaction works for aliphatic alkynes, but what if the alkyne has a phenyl attached? How will the aromatic ring affect the reaction of alkynes with water?
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1answer
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Protonation of Carbonyl oxygen in Fischer Esterification

In the Fischer Esterification, why is it the acid's carbonyl oxygen getting protonated and not the hydroxyl oxygen? This protonation occurs in Step 1 of the mechanism below. I read in some textbooks ...
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1answer
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Regioselectivity in Diels–Alder reaction between 2-nitrobuta-1,3-diene and acrylonitrile

Since $\ce{-CN}$ shows strong −I effect, there will be δ+ charge on the carbon adjacent to it. Similarly, $\ce{-NO2}$ shows strong −I and –M effects. So, I proposed that π-electrons are being donated ...
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Can secondary alkyl halides be used in the Corey–House synthesis?

I've been told by my teacher that the Corey–House synthesis cannot proceed with secondary alkyl halides; they will prefer to undergo elimination over $\mathrm{S_N2}$ substitution. [used as the pseudo ...
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Why does equilibrium for the addition of the Claisen enolate to an ester not favor the product?

I am currently reading chapter 26 of Clayden's Organic Chemistry, and a diagram for the elementary steps of the Claisen condensation with ethyl acetate in ethoxide is provided. It is obvious why the ...
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Mechanism for the Formation of DMC

I have recently reviewed the synthesis of the dehydrating agent DMC (7), but I could find no reported mechanisms for its formation. I have proposed the mechanism drawn below, but I am unsure about a ...
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What is the mechanism of benzyl ether hydrogenolysis?

The mechanism for the hydrogenation of alkenes or alkynes using Pd/C is fairly well explained to involve the absorption of hydrogen onto a metal's surface followed by the addition of that hydrogen ...
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Three-membered ring pathway bromination of alkene

Bromination of alkene occurs by the mechanism as shown (source: Master Organic Chemistry — Bromination of Alkenes: The Mechanism): Here $\ce{Br^-}$ attacks bromonium ion from a side which is more ...
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Do tert-butylcyclohexanes with a leaving group locked in the equatorial position undergo E1?

Background Elimination of 1-bromo-tert-butylcyclohexane is a prototypical example of how important the anti periplanar relationship is for E2. From Organic Chemistry: Structure, Mechanism, Synthesis ...
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Is there an adhesive that is not dissolved by acetone?

I am trying to glue glass sheets together to make a sealed 13" x 13" x 13" box. Inside this box there would be acetone gas used to melt 3D printed parts to make them more durable. Acetone will remove ...
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162 views

Condensation reaction between catechol and acetone

I was thinking of ways to synthesize 2,2-bis(dihydroxyphenyl) propane and I thought it could be made by a condensation reaction between dihydroxybenzene (catechol) and acetone in strongly acidic ...
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Curtin-Hammett principle to evaluate alkene insertion

Given an unsymmetrical alkene in a simple non-stereoselective catalytic hydrogenation reaction. If one would want to investigate the nuances in the catalytic cycle of a dihydride complex leading to ...
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377 views

Reaction mechanism of thiol to disulfide oxidation under basic conditions?

I have been looking everywhere for an explanation to a reaction mechanism concerning the oxidation of DTT (or just thiols to disulfides in general) using oxygen as the oxidant. I'm aware that ...
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141 views

What's the mechanism behind mineral oil loosening cyanoacrylate bonds?

Per industry literature I found that mineral oil is used to loosen out "super glue" and aid in removal from skin. I am exploring the chemistry of this loosening and I am intrigued. Please help me find ...
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Mechanism of DPD (N,N-diethyl-p-phenylenediamine) reaction with free chlorine

NOTE: As I've been finding new informations about the question, I've been editing the question to keep it up to date. If some comment doesn't make sense just check the Edit History. DPD (N,N-diethyl-...

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