3. Acids and Bases

For the following acid–base pairs, (v) show a mechanism for the reaction;

(e)

For practice in recognizing mechanisms, classify each reaction according to the type of mechanism you expect:

1. Free-radical chain reaction

2. Reaction involving strong bases and strong nucleophiles

3. Reaction involving strong acids and strong electrophiles

(a)

For practice in recognizing mechanisms, classify each reaction according to the type of mechanism you expect:

1. Free-radical chain reaction

2. Reaction involving strong bases and strong nucleophiles

3. Reaction involving strong acids and strong electrophiles.

(d)

Would you expect the following species to be electrophiles or nucleophiles? Some may be both. Explain your answer.

(h)

Predict the product that results from the following 'pushed electrons.'

(i)

Suggest an arrow-pushing mechanism for each of the following acid–base reactions

(c)

Label the reactants in these acid–base reactions as Lewis acids (electrophiles) or Lewis bases (nucleophiles). Use curved arrows to show the movement of electron pairs in the reactions.

(a)

Each of these compounds can react as a nucleophile. In each case, use curved arrows to show how the nucleophile would react with the strong electrophile BF₃.

(a)

(b)

Aluminum trichloride (AlCl₃) dissolves in ether with the evolution of a large amount of heat. (In fact, this reaction can become rather violent if it gets too warm.) Show the structure of the resulting aluminum chloride etherate complex.

Use curved arrows to show the flow of electrons that occurs in each step of the following mechanism

Identify the electrophile and the nucleophile in each of the following reaction steps. Then draw curved arrows to illustrate the bond-making and ­bond-breaking processes.

a.

BCl₃ has an empty p orbital, so it is a strong Lewis acid. Would you expect an amide to react with BCl₃ at nitrogen or oxygen?

Identify the electrophile and the nucleophile in each of the following reaction steps and then draw curved arrows to illustrate the bond-making and bondbreaking processes.

b.