Reactions of Alkyl Halides: Nucleophilic Substitutions and Eliminations

These flashcards cover key concepts regarding the reactivity of alkyl halides, including nucleophilic substitutions and elimination reactions.

What makes the carbon in alkyl halides electrophilic?

The polarization at the carbon-halide bond.

What type of reaction do nucleophiles perform with alkyl halides?

Nucleophiles replace the halide in C-X bonds, exhibiting nucleophilic substitution.

What is the relationship between nucleophilic substitution and elimination reactions?

Both are among the most widely occurring and versatile reaction types in organic chemistry.

What was shown by Walden in 1896 regarding malic acid?

That (-)-malic acid could be converted to (+)-malic acid through a series of chemical steps with achiral reagents.

What is a significant aspect of nucleophilic substitutions?

They can invert the configuration at a chirality center.

What is the order of reaction kinetics for an SN2 reaction?

The reaction follows second order reaction kinetics.

How does the reaction rate depend on concentration?

Rate decreases as concentrations decrease, but the rate constant remains unchanged.

What is the structural arrangement in the transition state of an SN2 reaction?

A roughly planar arrangement of the carbon atom and the three remaining groups.

What is the reactivity order for alkyl halides in SN2 reactions?

Methyl > Primary > Secondary > Tertiary.

What kind of leaving groups enhance the SN2 reaction?

Stable anions that are weak bases, allowing better charge delocalization.

How do polar aprotic solvents affect SN2 reactions?

They form weaker interactions with substrates, enabling faster reactions.

What is the mechanism type of SN1 reactions?

They involve a two-step process, starting with leaving group departure followed by nucleophile addition.

What happens to chirality during an SN1 reaction?

The reaction may lead to the formation of a racemic mixture or some inversion.

What is Zaitsev’s Rule in relation to elimination reactions?

The more highly substituted alkene product predominates in elimination reactions.

What is the difference between E1 and E2 mechanisms?

E1 involves a carbocation intermediate, while E2 involves a concerted transition state.

What is the stereochemistry requirement for an E2 elimination reaction?

The reactant must have anti periplanar geometry.

How do solvents affect SN1 reactions?

Solvent polarity and stability of the transition state significantly influence the reaction rate.