E2 Reaction : Second-Order Elimination

E2 Reaction : Second-Order Elimination

Second-Order Elimination: The E2 Reaction – Eliminations can also take place under second-order conditions with a strong base present. – As an example, consider the reaction of tert-butyl bromide with methoxide ion in methanol. – This is a second-order reaction because methoxide ion is a strong base as well as …

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E1 Reaction : First-Order Elimination

First-Order Elimination : The E1 Reaction – An elimination involves the loss of two atoms or groups from the substrate, usually with formation of a pi bond. – Elimination reactions frequently accompany and compete with substitutions. – By varying the reagents and conditions, we can often modify a reaction to …

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Comparison of SN1 and SN2 Reactions

Comparison of SN1 and SN2 Reactions Let’s compare what we know about the SN1 and SN2 Reactions and reactions, the organize this material into a brief table. (1) Effect of the Nucleophile on SN1 and SN2 Reactions – The nucleophile takes part in the slow step (the only step) of …

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Rearrangements in the SN1 Reactions

Rearrangements in the SN1 Reactions

Rearrangements in the SN1 Reactions – Carbocations frequently undergo structural changes, called rearrangements, to form more stable ions. – A rearrangement may occur after a carbocation has formed or it may occur as the leaving group is leaving. – Rearrangements are not seen in SN2 reactions, where no carbocation is …

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Stereochemistry of the SN1 Reactions

Stereochemistry of the SN1 Reaction – The SN2 reaction is stereospecific: the nucleophile attacks from the back side of the electrophilic carbon atom, giving inversion of configuration. – In contrast, the SN1 reaction is not stereospecific. – In the SN1 mechanism, the carbo-cation intermediate is sp2 hybridized and planar. – …

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SN1 Reaction – Nucleophilic Substitution reaction

SN1 Reaction: First-Order Nucleophilic Substitution – When tert-butyl bromide is placed in boiling methanol, methyl tert butyl ether can be isolated from the reaction mixture. – Because this reaction takes place with the solvent acting as the nucleophile, it is called a solvolysis (solvo for “solvent,” plus lysis, meaning “cleavage”) …

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Stereochemistry of the SN2 Reaction

Stereochemistry of the SN2 Reaction

Stereochemistry of the SN2 Reaction – As we have seen, the reaction SN2 requires attack by a nucleophile on the back side of an electrophilic carbon atom (see Figure) – A carbon atom can have only four filled bonding orbitals (an octet), so the leaving group must leave as the …

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Reactivity of the Substrate in SN2 Reactions

Reactivity of the Substrate in SN2 Reactions

Reactivity of the Substrate in SN2 Reactions – We will often refer to the alkyl halide as the substrate: literally, the compound that is being attacked by the reagent. – Just as the nucleophile is important in the SN2 reaction, the structure of the alkyl halide is equally important. – …

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SN2 reaction of Alkyl halides

SN2 reaction of Alkyl halides

In this subject Second-Order Nucleophilic Substitution: The SN2 Reaction of Alkyl halides will be discussed Reactions of Alkyl Halides: Substitution and Elimination – Alkyl halides are easily converted to many other functional groups. – The halogen atom can leave with its bonding pair of electrons to form a stable halide …

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Preparation of alkyl halides

Preparation of alkyl halides – Most Methods of preparation of alkyl halides exploit the chemistry of functional groups we have not yet covered. – For now, we review free-radical halogenation and only summarize other, often more useful, syntheses of alkyl halides. – The other Methods of preparation of alkyl halides …

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Physical Properties of Alkyl Halides

Physical Properties of Alkyl Halides will be discussed such as dipole moment, London force, Dipole–dipole attractions, densities of common alkyl halides. Structure of Alkyl Halides – In an alkyl halide, the halogen atom is bonded to an carbon atom. – The halogen is more electronegative than carbon, and the bond …

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Nomenclature of Alkyl Halides

Introduction to Alkyl Halides – In this subject , we consider Nomenclature of alkyl halides. – Our study of organic chemistry is organized into families of compounds classified by their functional groups. – We use alkyl halides to introduce substitution and elimination, two of the most important types of reactions …

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Essential terms in Stereochemistry

Essential terms in Stereochemistry

Essential terms in Stereochemistry stereochemistry – stereochemistry is The study of the three-dimensional structure of molecules. – It is the systematic presentation of a specific field of science and technology that traditionally requires a short preliminary excursion into history. – Stereochemistry is the (chemistry of space). – In this subject …

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