A study of new planar chiral monophosphine ligands based on [2.2]paracyclophane and their use in catalysis : Chemistry, Institute of Fundamental Sciences, Massey University : Masters thesis under the supervision of Dr. Gareth J. Rowlands
The Suzuki-Miyaura coupling reaction is one of the most powerful methods for the
construction of biaryls. The biaryl motif has great importance in pharmaceutical,
agrichemical and material science industries, and is often axially chiral. The outcome of a
Suzuki-Miyaura coupling reaction can be influenced by many factors, but the ligand plays the
most vital role. A large number of ligands have been developed, including many chiral
ligands for asymmetric reactions. While ligand design has focused on molecules containing
either central or axial chirality, little has been focused on planar chiral ligands.
In this project, three new ligands based on the [2.2]paracyclophane backbone have been
designed, pseudo-ortho substituted monophosphines (L1 and L2), secondary phosphine oxide
and arylindolyl phosphine ligands (L3 and L4). Unfortunately, similar analogues of L1 and
L2 were reported before our results, and a synthesis route to the secondary phosphine oxide
ligands was not achieved. The use of L1 in gold mediated cyclisation was investigated, which
concluded that L1 was not suitable for this kind of reaction. However, arylindolyl phosphine
ligands were prepared successfully, and produced promising preliminary results in achiral
Suzuki-Miyaura coupling reactions.
Interesting X-ray crystallography structure of brominated indole is discussed.