The development of Pd(II)-catalysed oxidative Heck reactions and C-H functionalisations
Abstract
This thesis outlines the work undertaken on three projects focusing on the development
of Pd(II)-catalysed oxidative Heck reactions and C-H functionalisations.
Chapter one reviews literature related to palladium catalysis, specifically the oxidative
Heck reaction, its development and the most recent advances in this area.
Chapter two describes methodology developed to switch the outcome of the ligand- and
base-free Pd(II)-catalysed reaction between cyclic enones and boronic acids from
conjugate addition to oxidative Heck product, by simply changing the solvent.
Additionally, factors which favour one reaction over the other are also discussed.
Chapter three outlines the successful development of a palladium-catalysed direct C-H
functionalisation of benzoquinone. Both mono and difunctionalisations can be carried
out selectively in excellent yields and a wide variety of functional groups are tolerated.
Regioselectivity of the difunctionalisation reactions appears to be determined by the
electronic properties of the boronic acid used. A successful one-pot procedure for the
heterodifunctionalisation of benzoquinone is also outlined.
Chapter four details the development of oxidative Heck reactions on challenging
2,2-disubstituted cyclopentene-1,3-dione substrates with aryl boronic acids. An
efficient enantioselective protocol provides a facile way to desymmetrise the all carbon
quaternary stereocentre present in the cyclopentenedione substrates and includes the
synthesis of (+)-preussidone.