Grignard Reagents are also used in the following important reactions: The addition of an excess of a Grignard reagent to an ester
or lactone gives a tertiary alcohol in which two alkyl groups are the same, and the addition of a Grignard reagent to a nitrile produces
an unsymmetrical ketone via a metalloimine intermediate.
The traditional version of the Ullmann reaction requires harsh reaction conditions, and the reaction has a reputation for erratic yields.
Since its discovery some improvements and alternative procedures have been introduced.
4. Lithium n-butyl reaction
![Lithium n-butyl reaction]()
5. Vilsmeier-haack reaction
![Vilsmeier-haack reaction]()
The Vilsmeier–Haack reaction (also called the Vilsmeier reaction) is the chemical reaction of a substituted amide with
phosphorus oxychloride and an electron-rich arene to produce an aryl aldehyde or ketone.
The reaction is named after Anton Vilsmeier and Albrecht Haack. The reaction of a substituted amide with phosphorus oxychloride
gives a substituted chloroiminium ion, also called the Vilsmeier reagent. The initial product is an iminium ion (4b), which is
hydrolyzed to the corresponding aromatic ketone or aldehyde during workup.
Application
* One recent application of this reaction involved a new synthetic route to tris(4-formylphenyl)amine from triphenylamine which by
known procedures resulted in a poor chemical yield of 16%.
* It was found that this low yield was caused by deactivation of the remaining benzene ring by the imine groups on the other two
phenyl groups in the third formylation step.
* The procedure was modified by taking the reaction to di-imine compound followed by hydrolysis to the di-formyl compound
and then (with final position reactivated) a separate formylation to the tri substituted compound.
6. Witting reaction
![Witting reaction]()
The Wittig reaction or Wittig olefination is a chemical reaction of an aldehyde or ketone with a triphenyl phosphonium ylide (often
called a Wittig reagent) to give an alkene and triphenylphosphine oxide.
Wittig reactions are most commonly used to couple aldehydes and ketones to singly substituted phosphine ylides.
With unstabilised ylides this results in almost exclusively the Z-alkene product. In order to obtain the E-alkene, stabilised ylides are used or unstabilised ylides using the Schlosser modification of the Wittig reaction can be performed.
7. Buchwald-Harting reaction
![Buchwald-Harting reaction]()
The Buchwald–Hartwig is a chemical reaction used in organic chemistry for the synthesis of carbon-nitrogen bonds via the
palladium-catalyzed cross-coupling of amines with aryl halides.
The development of this reaction allowed for the facile synthesis of aryl amines, replacing to an extent harsher methods (the
Goldberg reaction, nucleophilic aromatic substitution, etc.) while significantly expanding the repertoire of possible C–N bond formation.
8. Bromination
![Bromination]()
Bromination is a chemical reaction where a bromine atom is integrated into a molecule.
9. Iodination
![Iodination]()
Hydrazone iodination or Iodination is an organic reaction in which a hydrazone is converted into a vinyl iodide by reaction of iodine
and a non-nucleophilic base such as DBU.
10. Esterification
![Esterification]()
Esterification is a Chemical Reaction Used for Making Esters. Esterification is the general name for a chemical reaction in which
two reactants (typically an alcohol and an acid) form an ester as the reaction product.
This leads to their extensive use in the fragrance and flavor industry. Esterification is a reversible reaction.
11. Friedel-Crafts reaction
![Friedel-Crafts reaction]()
This reactions are a set of reactions developed by Charles Friedel and James Crafts in 1877 to attach substituents to an aromatic
ring.
There are two main types of Friedel-Crafts reactions:
alkylation reactions and acylation reactions, both preceded by electrophilic aromatic substitution.
Friedel-Crafts reactions have been used in the synthesis of several triarylmethane and xanthene dyes.
Friedel-Crafts test for aromatic hydrocarbons.
12. Oxidizing reaction
![Oxidizing reaction]()
Oxidation is the loss of electrons or an increase in oxidation state by a molecule, atom, or ion. Oxidants are usually chemical
substances with elements in high oxidation states (Such as H2O2) or or else highly electronegative elements (O2) that can gain
extra electrons by oxidizing another substance.
Oxidation is used in a wide variety of industries such as in the production of cleaning products and oxidizing ammonia to produce
nitric acid, which is used in most fertilizers.
13. Wolff-Kishner-HuangMinlong reaction
![Wolff-Kishner-HuangMinlong reaction]()
The Wolff-Kishner reduction is a chemical reaction that fully reduces a ketone (or aldehyde) to an alkane.
The Huang–Minglon modification (after Huang Minglon) is a convenient modification of the Wolff-Kishner reduction and involves
heating the carbonyl compound, potassium hydroxide, and hydrazine hydrate together in ethylene glycol in a one-pot reaction.
14. Baeyer-Villiger reaction
![Baeyer-Villiger reaction]()
The Baeyer-Villiger oxidation is an organic reaction in which a ketone is oxidized to an ester by treatment with peroxy acids
or hydrogen peroxide. Key features of the Baeyer-Villiger oxidation are its stereospecificity and predictable regiochemistry.
This reaction is also called Baeyer-Villiger rearrangement.
15. Williamson reaction
![Williamson reaction]()
The Williamson ether synthesis or Williamson reaction is an organic reaction, forming an ether from an organohalide and an
alcohol. This reaction is important in the history of organic chemistry because it helped prove the structure of ethers.
The general reaction mechanism is as follows:
![The general reaction mechanism of Williamson reaction]()
The Williamson reaction is of broad scope, is widely used in both laboratory and industrial synthesis, and remains the simplest
and most popular method of preparing ethers.
16. Reduction reaction
![Reduction reaction]()
Reduction is the gain of electrons or a decrease in oxidation state by a molecule, atom, or ion. The meaning of reduction then
became generalized to include all processes involving gain of electrons.
17. Nitration
![Nitration]()
Nitration is a general class of chemical process for the introduction of a nitro group into an organic chemical compound. More
loosely the term also is applied incorrectly to the different process of forming nitrate esters between alcohols and nitric acid, as
occurs in the synthesis of nitroglycerin. The difference between the resulting structure of nitro compounds and nitrates is that the
nitrogen atom in nitro compounds is directly bonded to a non-oxygen atom, typically carbon or another nitrogen atom, whereas
in nitrate esters, also called organic nitrates, the nitrogen is bonded to an oxygen atom that in turn usually is bonded to a carbon
atom.
There are many major industrial applications of nitration in the strict sense; the most important by volume are for the production
of Nitroaromatic compounds such as nitrobenzene. Nitration reactions are notably used for the production of explosives, for
example the conversion of guanidine to nitroguanidine and the conversion of toluene to trinitrotoluene. However, they are of wide
importance as chemical intermediates and precursors. Millions of tons of nitroaromatics are produced annually.
18. Acylation reaction
![Acylation reaction]()
In chemistry, acylation (rarely, but more formally: alkanoylation) is the process of adding an acyl group to a compound. The
compound providing the acyl group is called the acylating agent. Because they form a strong electrophile when treated with some
metal catalysts, acyl halides are commonly used as acylating agents.
Acyl halides and anhydrides of carboxylic acids are also commonly used acylating agents to acylate amines to form amides or
acylate alcohols to form esters. Succinic acid is also commonly used in a specific type of acylation called succination.
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