Lecture 7 Flashcards
1
Q
How is reactivity dictated?
A
By polarisation effects
2
Q
What oxidation state is the Ln in?
A
+3 oxidation state
3
Q
What are the two steps used to start building catalytic cycles?
A
- insertion
- sigma bond metathesis
4
Q
What is the nature of a Ln catalyst?
A
- fast ligand exchange
- highly reactive
- low functional group tolerance
- no redox potentials so ox add and red elim can’t occur
5
Q
how is regiochemistry determined?
A
- by the stabilising groups involved in the reaction
- consider conjugation etc when looking at a reaction
6
Q
When does polymerisation occur?
A
If the rate of insertion is much greater than the rate of sigma bond metathesis
7
Q
Name two selective oxidising agents
A
CAS and CAN
8
Q
What reaction does Kagan’s reagent perform?
A
Effective as a reducing agent
9
Q
How are Ce(III) salts used in organic synthesis
A
- favour 1,2 over 1,4 addition due to hard hard reactions
- e.g. leuche reaction
10
Q
How are trivalent Ln 3+ ions used in organic synthesis
A
- as Lewis acid catalysts
- in addition to chiral ligands in asymmetric catalysts
