This chapter explores the synthesis of amines. It explains how amines are accessible from three main sources: basic amine building blocks, synthetizsation of the amino group to a suitable precursor, and yielding more complex amines after being alkylated. Additionally, the chapter discusses the synthesis of amines through reduction reactions and substitution reactions via amines or ammonia. It also looks into using mononucleophilic ammonia using five widely used methods such as the classical Gabriel method. Next, the chapter looks at the two methods of preparing amines: are nucleophilic displacement using nitrogen from a nucleophilic source and reduction of a nitrogen-containing functional group. The chapter examinies the factors to consider when looking into unsaturated nitrogen compounds.
Chapter
Imines
Chapter
Competing reactions
This chapter explores the possible outcomes for a given set of reactions. It examines the reactions of carbonyls with hydroxide which would result in the formation of enolates, isotopic labelling, and energy profiles for alternative reactions. The chapter notes how reactions can be manipulated by changing the alkylating agent and changing the solvent. It explains how unsymmetrical enolates will be formed following the removal of hydrogen from unsymmetrical ketones. Thermodynamic and kinetic products also impact the formation of enolates. In addition, the chapter looks at how substitution and elimination could incite various reactions. It concludes by examining the importance of chemists understanding why and how reactions occur.
Chapter
Halogenoalkanes
This chapter explains the concept of halogenoalkanes which have carbon-halogen bonds which are significantly polar. However, the carbon atom is partially positively charged and susceptible to a nucleophilic attack. The chapter explains that carbon-halogen bond enthalpy determines the relative rate of reaction. The three common nucleophilic substitution reactions of halogenoalkanes involve sodium hydroxide, potassium cyanide, and ammonia. Elimination is the second vital characteristic type of reaction of halogenoalkanes as it produces an alkene. The hydroxide ion is acting as the base of the compound rather than a nucleophile. Elimination is favoured over substitution where we see nucleophiles with strong bases, bulky nucleophiles, and high temperatures.
Chapter
Alcohols
This chapter focuses on alcohols (ROH) which have at least one hydroxyl group bonded to a carbon atom. Alcohols are known to undergo two reactions similar to the reactions of halogenoalkanes. Additionally, esters are formed through an alcohol's reaction to carboxylic acids. Alcohols also undergo oxidation reactions. The chapter explores the main manufacturing processes for ethanol which are fermentation and the direct hydration of ethene. It also considers the nucleophilic substitution and oxidation reactions of alcohols. The elimination reactions coincide with alcohol being dehydrated through heating with acid. However, conditions depend on the specific alcohol involved in the process as some of the alcohols could produce more than a single product.
Chapter
Algebra VII
Solving simultaneous linear equations
This chapter describes the process of solving simultaneous linear equations. ‘Linear’ means the equations have variables of the form x and y associated with a straight line rather than curved lines — finding the common value when one or more of the lines is curved requires a different procedure. Solving simultaneous linear equations involves elimination and substitution. We can achieve elimination by subtracting like terms from between the two equations. The chapter then looks at the situation in which there are two equations and two unknowns. It considers the process of solving simultaneous linear equations graphically, with algebra, with negative coefficients, with factors, and with generalized equations.
Chapter
Integration
This chapter evaluates integration, starting with a discussion of areas and integrals. It explains that Itntegration deals with the 'area under a curve', which; this is intimately linked with the important questions of the average and cumulative behaviour of y, over some range in x. Although an integral is defined as the limiting form of a summation, it is usually evaluated by noting that 'integration is the reverse of differentiation'. The chapter clarifies that, Jjust as for the case of derivatives, one of the most fundamental properties of integrals is their linearity. The chapterIt then looks at inspection and substitution, partial fractions, integration by parts, and the reduction formula. Finally, the chapter examines symmetry, tables, and numerical integration.
Chapter
Reaction mechanisms: the chemical changes that drive the chemistry of life
This chapter examines four key reaction mechanisms: substitution, addition, elimination, and condensation. During substitution, an atom or group of atoms from one reactant is substituted for an atom or group of atoms on a second reactant molecule. Substitution may be electrophilic or nucleophilic, depending on the nature of the molecule that changes as a result of the reaction. During an addition reaction, two molecules combine in such a way that the product contains all the atoms of both reactants. By contrast, during an elimination reaction, a reactant loses some of its component atoms; these atoms form one or more new compounds. Elimination may proceed via a two-step E1 mechanism, or a one-step E2 mechanism. Finally, during a condensation reaction, two reactants combine to form a single product; a further molecule is eliminated during the reaction, which forms an additional product. The chapter then considers hydrolysis reactions and how biochemical reactions exemplify the reaction mechanisms discussed earlier in the chapter.
Chapter
The effects of the solvent
This chapter focuses on the effects of the solvent. It regards solvent as a crucial component of reactions while referencing the reaction of t–butyl chloride. The rate of formation of either the substitution or elimination product depends only on the rate of the initial step. The chapter highlights the importance of the solvent being a result of the solubility of one substance in another. It lists different types of solvent as they are classified through their polarity and relative permittivity. Types of solvents include hydrogen bonds, protic solvents, and aprotic solvents. Additionally, the chapter examines the solvating of different ions, acid strengths, and the role of solvents while noting the impact of solvents on the rate of reactions.
Chapter
Nucleophilic Substitution Reactions of Haloalkanes and Related Compounds
Tadashi Okusecyama and Howard Maskill
This chapter covers the substitution reactions of haloalkanes and related compounds under nucleophilic/basic conditions. It emphasizes that haloalkanes and related compounds containing a single bond from a saturated (sp3) carbon to a heteroatom can be represented generically as RY, where R is alkyl and Y is a halogen. The chapter then highlights the two most characteristic reactions of RY (substitution and elimination) under nucleophilic/basic conditions, both involve heterolysis of the bond from the electrophilic carbon to the heteroatom and departure of the nucleofuge. In substitutions, the nucleofuge is replaced by a nucleophile at the α C. However, as the chapter reveals, another substitution mechanism (SN1) is also possible depending upon the structure of RY and the reaction conditions. The chapter discusses both mechanisms, and explores the relationships between them. Next, the chapter analyzes the stereochemistry of substitution at saturated carbon, and the solvent effects upon substitution reactions.
Chapter
Elimination Reactions of Haloalkanes and Related Compounds
Tadashi Okusecyama and Howard Maskill
This chapter looks at the mechanisms of elimination reactions of unimolecular elimination (E1), bimolecular elimination (E2), and E1 conjugate base or E1cB. Just as in substitution, there is some mechanistic diversity amongst elimination reactions and, because nucleophiles often also act as bases, substitution and elimination reactions of compounds RY are generally in competition with each other. The chapter covers the mechanisms of elimination reactions of RY (principally haloalkanes) to give alkenes. It also investigates the relationships between these and substitution reaction mechanisms covered in the previous chapter. Finally, the chapter shifts to elaborate on regioselectivity in elimination reactions, and competition between substitution and elimination.
