Nucleophilic Attack On Pi Systems

Question 1

How to make a-B-unsaturated carbonyl

Answer 1

Carbonyl + NaOH

Self condensation

Question 2

Good conjugate acceptor

Answer 2

More -ve pKa

Can stabilise -ve charge better

Question 3

Direct addition

Answer 3

Kinetic product

Question 4

Conjugate addition

Answer 4

Thermodynamic product

Question 5

To get kinetic product

Answer 5

Low temp

Short reaction times

Question 6

To get thermodynamic product

Answer 6

Higher temps

Long reaction times

Question 7

Exception to direct/conjugate kinetic/thermodynamic rule

Answer 7

Amines- conjugate is kinetic and thermodynamic

Question 8

Hard nucleophile

Answer 8

Small
-ve charge
Basic
Low energy HOMO

Question 9

Hard electrophile

Answer 9

Small
+ve charge
High energy LUMO

Question 10

Soft nucleophile

Answer 10

Larger
Uncharged
Less electronegative
High energy HOMO

Question 11

Soft electrophile

Answer 11

Larger
Uncharged
Polarisable electrons
Low energy LUMO

Question 12

Hard reactions dominated by

Answer 12

Electrostatic interactions

Under charge control

Question 13

Soft reactions dominated by

Answer 13

HOMO-LUMO interactions

Under orbital control

Question 14

B-carbon=

Answer 14

Soft

Question 15

B-carbon=

Answer 15

Soft

Question 16

Carbonyl carbon=

Answer 16

Hard

Question 17

Carbonyl derivatives and reactivity

Answer 17

More reactive carbonyl group (more d+ C) -> more direct addition