Novel bulky fluorinated ligands for homogeneous catalysis

Ligands--Synthesis;Phosphorus compounds;Catalysis

Frew, Jamie J. R. ; Clarke, Matt ; Clarke, Matt

University:University of St Andrews

Department:Chemistry (School of)

关键词: Ligands--Synthesis;    Phosphorus compounds;    Catalysis;   

Others  :  https://research-repository.st-andrews.ac.uk/bitstream/handle/10023/852/JamieFrewPhDThesis.pdf?sequence=3&isAllowed=y

来源: DR-NTU

【 摘 要 】

A series of novel monodentate and bidentate phosphine ligands substituted with bulkytert-butyl and fluorinated aryl groups have been synthesised. Borane protection hasproved to be an excellent method for easy synthesis and purification of bidentate ligandsin some cases. However, several of the bulky fluorinated ligands do not form stableborane complexes leading to complications in the synthesis and purification of thesecompounds. By reaction with transition metal platinum and palladium precursors, it waspossible to form dichloride complexes from the synthesised ligands, which werecharacterised by X-ray crystallography. The complexes were found to be effectivecatalysts for the hydroxycarbonylation of vinyl arenes (yields of up to 95 % with 3mol% catalyst). An unsymmetrical bidentate complex (3.18) in combination with paratoluenesulfonicacid and LiCl promoters has given exceptional (for a diphosphine ligand)regioselectivity for the branched acid (98.7 % branched) in the hydroxycarbonylation ofstyrene. The role of the promoters has been found to be crucial in deciding the activityand selectivity in this reaction.