Niobium and tantalum have been used for a number of catalytic reactions. These mclude carbon monoxide reduction, dimensation and polymerisation of olefins, oligomerisation and polymerisation of acetylenes, nucleophilic Wittig-type reactions, hydrogenation of arenes and aryl phosphmes, hydrodemtrogenation and hydroboration reactions. In this work their potential as enantioselective catalysts was investigated. The metal chlorides displayed Lewis-acid activity and they were used, in conjunction with a number of chiral ligands, in the catalysis of the Diels-Alder reaction between cyclopentadiene and either crotonaldehyde or methacrolem. A number of ammo acids were investigated and, although Lewis-acid activity was evident from the yield at low temperature and from the endo.exo ratios, no chiral induction was achieved. When Cisymmetncal tartrate esters were used ee’s of 22 and 40% m the presence of niobium pentachlonde were achieved for the ethyl and i-propyl esters respectively Chiral Schiff bases were synthesised by a condensation reaction between salicylaldehyde or tbutyl salicylaldehyde and a number of ammo alcohols. The complexes formed between these compounds and either niobium pentachlonde or niobium pentawopropoxide failed to give enantiomeric excess in the test reaction Pyndme-fos-oxazoline (Pybox) ligands were synthesised and, along with the Jacobsen ligand, complexes were formed with niobium and tantalum pentachlonde. One such complex, that between NbCls and R, /?-Jacobsen ligand was isolated and charactensed. These complexes did provide enantiomenc excess m the test reaction. The extent of the ee was dependent on the ligand used, whether co-catalyst was added and whether 4A molecular sieves were mcluded. The best results achieved were with the Jacobsen ligand where up to 52% ee was achieved. In a second part of the work an attempt was made to design a catalytic system whereby the effects of central, planar and helical chirality in the catalyst could be compared. The enantioselective epoxidation of olefins was chosen as the test reaction and bis sandwich complexes of niobium and tantalum as the test catalysts. Attempts were made to synthesise unsymmetncal sandwich complexes containing cyclopentadienyl and mdenyl ligands, leading to the formation of peroxometallic species These were, however, unsuccessful. An attempt was made to synthesise a heptahelicene with terminal five-membered nngs A literature method was first used. Tins proved to be difficult to emulate and thus a different method was devised. However this also proved to be unsuccessful It was not possible to perform the chirality companson experiments.