Nucleophilic Phosphine Organocatalysis

1
Nucleophilic Phosphine Organocatalysis

• Thursday 8th December
• Lisa Pattenden

2
Revision of Common Phosphine Reactions in
Synthesis
3
Rauhut-Currier Dimerisation of Activated Alkenes
4
Dimerisation Applied to Large Scale synthesis
5
Crossed Rauhut-Currier Reaction
6
Intramolecular Rauhut-Currier Reaction
7
Morita-Baylis-Hillman Reaction
8
Asymetric Morita-Baylis-Hillman Reaction
9
Isomerisation of Alkynes
10
Discovery of Reactions without Palladium catalyst
11
Proposed Mechanism Using Stoichiometric
Triphenylphosphine
12
Synthesis of Substituted Furans
13
Proposed Mechanism
14
Proposed Mechanism from the Allene Intermediate
15
Isomerisation using a Catalytic Amount of
Phosphine
16
Proposed Mechanism
17
Proposed Allene Intermediate was Subjected to
Phosphine
18
Addition of Oxygen Nucleophiles to Alkynes
19
Addition of Oxygen Nucleophiles to Alkynes
Proposed Mechanism
20
Lu Synthesis of Cyclopentenes from 32
Cycloadditions
21
Proposed Mechanism For 32 Cycloaddition
22
Construction of Spirocycles via 32
Cycloadditions
23
Pyne 32 Cycloadditions
24
Pyne 32 Cycloadditions
25
Pyne 32 Cycloadditions
26
Pyne 32 Cycloadditions
27
Lu Synthesis of Substituted Heterocycles using
32 Approach
28
By Products Formation
29
Synthesis of Tetrahydropyridines from a 42
Cycloaddition
30
42 Cycloaddition applied to Formal Synthesis
of ()-Alstonerine
31
Ireland-Type 3,3 Rearrangement of Allylic
Acrylates
32
Proposed Rearrangement Mechanism
33
Nucleophilic Phosphine Catalysis Summary

• Nucleophilic Addition Reactions at the a and g
  positions of unsaturated carbonyl compounds
• Cycloadditions 32 and 42 of activated
  alkenes and alkynes
• Reviews
• Nucleophilic Phosphine Organocatalysis, J.
  Methot, W. Roush, Adv. Synth. Catal., 2004, 346,
  1035.
• Reactions of Electron-Deficient Alkynes and
  Allenes under Phosphine Catalysis, X. Lu, C.
  Zhang, Z. Xu, Acc. Chem. Res., 2001, 34, 535.
• pKa values for tertiary phosphines,
  Organometallics, 1989, 8, 1.