Covalent catalysis

Question 1

Covalent catalysis two parts

Answer 1

• nucleophilic and electrophilic parts and the variations are based on the rate determining step

Question 2

Nucleophilic CC

Answer 2

need high nucleophilicity…rate increases with lewis basicity(related to nucleophilicity)…

nucleohilicity is a KINETIC parameter… lewis basicity is a THERMODYNAMIC parameter

Question 3

Polarizability

Answer 3

Polarizability is how easily the electrons can be distorted

Question 4

Nuc catalysis needs…

Answer 4

1. high nucleophilicity
2. polarizability (anything that involves resonance with more than 3 atoms)
3. good leaving group

Question 5

nucleophilic CC steps

Answer 5

1. nuclephilic rxm forming catalyst substrate bond
2. electron withdrawal by the NOW electrophilic catalyst acting as an electron sink (where the electrons are reacting)
3. catalyst product breaks (need good leaving group)