Halide Functional group transformation lists all halide involved transformation to help students while the organic synthesis of molecules.

Malonic ester synthesis

The alkylation of malonic ester enolates with various organic halides and the subsequent decarboxylation of the alkylated products to yield substituted acetic acid derivatives.

organic halides here is 1° and 2° alkyl halides and allylic and benzylic halides react the fastest, while tertiary alkyl halides mainly give elimination products

The order of reactivity of the halides is I ~ OTs > Br > Cl

Takai-Utimoto olefination

The chromium(II)-mediated one-carbon homologation of aldehydes with haloform to give the corresponding (E)-alkenyl halides

The rate of the reaction is a function of the haloform used: I>Br>Cl

The (E/Z) ratio is also dependent on the haloform used (Cl>Br>I)

Doering-LaFlamme allene synthesis

The preparation of allenes from olefins via dihalocyclopropanes

Tsuji-Wilkinson decarbonylation

The decarbonylation of aldehydes and acyl halides using Wilkinson’s catalyst

Schotten-Baumann reaction

. The synthesis of esters from alcohols and amides from amines with acyl halides or anhydrides in the presence of an aqueous base

The order of reactivity for alcohols is: 1°>2°>3°

The nucleophilicity of the amino group is far greater than that of the hydroxyl groups, the acylation took place selectively

Friedel-Crafts acylation

Introduction of a keto group into an aromatic or aliphatic substrate by using an acyl halide or anhydride in the presence of a Lewis acid catalyst

Reactivity order (I > Br > Cl > F)

Negishi cross-coupling

The Pd- or Ni-catalyzed stereoselective cross-coupling of organozincs and aryl-, alkenyl-, or alkynyl halides

Finkelstein reaction

Equilibrium exchange of the halogen atom in alkyl halides for another halogen atom .

Kornblum oxidation

The oxidation of alkyl halides to the corresponding carbonyl compounds using DMSO as the oxidant

The oxidation of alkyl halides to the corresponding carbonyl compounds using DMSO as the oxidant. tertiary alkyl halides do not react

The relative reactivity of the substrates is the following: tosylate>iodide>bromide>chloride

Wurtz coupling

Coupling of two sp3-carbon centers by the treatment of alkyl or benzyl halides with sodium metal.

Acetoacetic ester synthesis

Preparation of ketones via the alkylation of esters of acetoacetic esters

Friedel-Crafts alkylation

The substitution of aromatic and aliphatic substrates with various alkylating agents (alkyl halides, alkenes, alkynes, alcohols, etc.) in the presence of catalytic amounts of Lewis acid

reactivity of alkyl halides is (F > Cl > Br > I)

tertiary, benzyl > secondary > primary;

Stork enamine synthesis

The synthesis of α-alkyl- or acyl carbonyl compounds via the alkylation or acylation of the corresponding enamines

Activated alkyl and acyl halides are the best reactions partners (e.g., allyl-, benzyl-, propargylic-, or activated aryl halides);

Tertiary alkyl halides do not alkylate the enamines but rather undergo elimination;

Gabriel synthesis

Two-step preparation of primary amines from the corresponding alkyl halides,

Potassium phthalimide is first alkylated and the resulting N-alkylphthalimide is subsequently hydrolyzed

Sterically unhindered 1°and 2° alkyl halides give the best results with alkyl iodides being the most reactive (I > Br > Cl) followed by allylic, benzylic, and propargylic halides;

Williamson ether synthesis

The reaction of aliphatic or aromatic alkoxides with alkyl, allyl, or benzyl halides to afford the corresponding ethers

The order of reactivity for the halides regarding the alkyl group: Me>allylic~benzylic>1° alkyl>2°alkyl while under standard conditions tertiary alkyl halides undergo E2 elimination

Tthe order of reactivity is also influenced by the nature of the
leaving group: OTs~I>OMs>Br>Cl;

Arbuzov reaction

The synthesis of pentavalent alkyl phosphoric acid esters from trivalent
phosphoric acid esters and alkyl halides

It usually proceeds well with primary alkyl halides (mainly iodides and bromides);

Secondary and tertiary alkyl halides the reaction does not take place or alkenes are formed

Wagner-Meerwein rearrangement

Generation of a carbocation followed by the [1,2]-shift of an adjacent carbon-carbon bond to generate a new carbocation

[1,2]-alkyl, -aryl- or hydride shift to afford a more stable carbocation, ring expansion of strained small rings such as cyclopropanes and cyclobutanes to give more stable five- or six-membered products, collapse by fragmentation, etc.

Heck reaction

Yhe palladium-catalyzed arylation or alkenylation of olefins

The reaction conditions tolerate a wide range of functional groups on the olefin component: esters, ethers, carboxylic acids, nitriles, phenols, dienes,
etc., are all well-suited for the coupling, but allylic alcohols tend to rearrange;

More substituted olefin undergoes a slower Heck reaction; unsymmetrical olefins (e.g., terminal alkenes) predominantly undergo substitution at the least substituted olefinic carbon;

Reaction rates change in the following order: I > Br ~ OTf >> Cl

Kumada cross-coupling

Stereoselective cross-coupling reaction between aryl- or alkenyl halides and Grignard reagents in the presence of a catalytic amount of a nickel-phosphine complex

PRACTICE

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