Organic Chemistry: Alkyl Halides and Reactions

An organic compound that contains at least one carbon-halogen (C-X) bond, where X represents a halogen atom like fluorine (F), chlorine (Cl), bromine (Br), or iodine (I).

The process of creating an alkyl halide by replacing a hydrogen atom in an alkane with a halogen atom (Cl or Br) using heat or light. This involves a free radical mechanism.

A chemical compound derived from an alkane by replacing one or more hydrogen atoms with halogen atoms.

A series of reactions that involve forming a bond between a halogen atom and a carbon atom in an alkane. These reactions are usually initiated by heat or light and involve free radicals.

In radical halogenation, the replacement of a hydrogen atom at a more substituted carbon (carbon with more carbon atoms attached) is more likely to occur than at a less substituted carbon.

The tendency for a specific atom within a molecule to react with a reagent. It can be described as a measure of how easily a given atom undergoes a particular reaction, such as halogenation.

The process of adding a bromine atom to an alkene at the carbon atom adjacent to the double bond (allylic position). It involves using N-bromosuccinimide (NBS) and requires light for activation.

A type of chemical species that has a single unpaired electron. The allyl radical is particularly stable due to its delocalized electron, which can move across three carbon atoms.

The ability of the allyl radical to distribute its electron across three carbon atoms, making it more stable compared to other similar radicals. This stabilization arises from resonance stabilization.

The reaction of a primary or secondary alcohol with HX (HCl or HBr) often leads to rearrangements. This is because the carbocation intermediate formed during the reaction is prone to rearrangements, resulting in a different product than expected.

A reaction where a carbon-halogen bond (C-X) is replaced by a carbon-carbon bond (C-C), typically using a metal-containing reagent.

A reagent that contains a carbon-metal bond (C-M), where M is typically magnesium (Mg) or lithium (Li). It's very reactive and useful for forming new carbon-carbon bonds.

A specific type of organometallic reagent formed by reacting an alkyl halide (RX) with magnesium (Mg) in an ether solvent. These reagents are highly reactive and used for forming new carbon-carbon bonds.

A versatile reaction used to form carbon-carbon bonds between an aryl or vinyl boron compound and an aryl or vinyl halide. It requires a palladium catalyst and base.

An organometallic reagent formed by reacting an alkyllithium (RLi) with copper iodide (CuI). They are useful for forming carbon-carbon bonds, especially in reactions involving ketones and aldehydes.

A reaction in which a carbon-halogen (C-X) bond is broken, and the halogen is replaced by a nucleophile. The nucleophile attacks the carbon atom, leading to an inversion of configuration at the carbon center.

The rate of a chemical reaction, which is the change in concentration of reactants or products over time. For SN2 reactions, the rate depends on the concentrations of both the alkyl halide and the nucleophile.

The arrangement of atoms in the transition state of an SN2 reaction. It resembles a planar structure with the carbon atom and three other groups in one plane. The nucleophile and the leaving group are partially bonded to the carbon.

How easily a molecule reacts in an SN2 reaction. The SN2 reaction is sensitive to the number of alkyl groups attached to the carbon atom with the leaving group. More alkyl groups hinder the reaction.

A shorthand notation used to describe the characteristic step in nucleophilic substitution reactions. 'S' stands for substitution, 'N' stands for nucleophilic, and the number indicates the molecularity of the reaction.

A reaction that involves the breaking of a carbon-halogen bond and the formation of a double bond (C=C). The nucleophile acts as a base to remove a proton from a carbon atom adjacent to the carbon-halogen bond.

The tendency of a compound to undergo oxidation or reduction. Oxidation is the loss of electrons (gain of oxygen, nitrogen, or halogen), while reduction is the gain of electrons (loss of oxygen, nitrogen, or halogen).

A molecule that has a positive charge on a carbon atom, making it susceptible to attack by nucleophiles. Alkyl halides are examples of electrophiles.

The speed of a reaction is influenced by the number of alkyl groups directly attached to the carbon undergoing the reaction. More alkyl groups lead to a slower reaction due to steric hindrance, making it harder for the nucleophile to approach the carbon.

Nucleophiles with negative charges are generally more reactive than neutral nucleophiles with lone pairs. This is because the negative charge makes them more attracted to the positively charged electrophilic carbon in the reaction.

A good leaving group is one that can easily detach from the molecule, leaving behind a stable anion. These groups tend to be weak bases, meaning they are less likely to attract the positive charge of the carbon.

Protic solvents (like water or alcohols) can slow down SN2 reactions by forming hydrogen bonds with the reactants. This interaction makes it harder for the nucleophile to access the carbon.

Polar aprotic solvents (like acetone or DMF) are better for SN2 reactions because they have weaker interactions with the reactants, allowing the nucleophile to approach the carbon more easily.

SN1 reactions occur in two steps. First, the leaving group departs, forming a carbocation intermediate. Then, the nucleophile attacks the carbocation.

Tertiary alkyl halides are the most reactive in SN1 reactions because the resulting carbocation is the most stable. This is because the alkyl groups donate electron density, making the positive charge less concentrated.

SN1 reactions are faster in polar protic solvents because these solvents stabilize the carbocation intermediate, making the reaction more favorable.

In an elimination reaction, a hydrogen atom and a leaving group are removed from adjacent carbon atoms, forming a double bond (alkene). Competition between elimination and substitution reactions can reduce the yield of desired products.

Zaitsev's Rule states that the most substituted alkene (the one with more alkyl groups attached to the double bond) will be the major product in an elimination reaction.