Chiral counter-ion controlled asymmetric electrocyclic reactions

Thesis

The aim of this project was to develop new catalytic methods to control asymmetry in electrocyclic reactions, and to apply these methods to generate complex molecules. Initial efforts were directed towards the catalysis of anionic 8π electrocyclizations (Chapter 2 and Figure i).

8π electrocyclization was not achieved due to issues with alkene geometry and anion stability. Our efforts were then directed towards using phase-transfer catalysis to generate complex polycyclic compounds via a cascade electrocyclization-1,4-addition (Chapter 3 and Figure ii).

Pyrrolidines and indolizidines were generated in excellent yield from simple starting-materials with high levels of stereocontrol. Finally, we investigated the catalysis of a 6π [1,6] electrocyclization to generate dihydroquinolones (Chapter 4 and Figure iii).

A novel BINOL-derived copper(II) catalyst was developed, and afforded dihydroquinolones directly from their amine and aldehyde precursors with good yields and enantioselectivities.

Authors: Knipe, P; Peter Clarke Knipe

• Publication date: 2012
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: Oxford University, UK
• Language: English
• Keywords: catalysis; asymmetric; electrocyclization; organic
• Subjects: Heterocyclic chemistry; Organic chemistry; Organic synthesis; Chemistry & allied sciences; Asymmetric catalysis; Catalysis; Synthetic organic chemistry; Electrocyclization