Functionalised N-heterocyclic carbenes and amido/imino mixed donors as supporting ligands in organometallic catalysis

Winston, Scott (2003) Functionalised N-heterocyclic carbenes and amido/imino mixed donors as supporting ligands in organometallic catalysis. University of Southampton, Doctoral Thesis.

Record type: Thesis (Doctoral)

Abstract

Novel nitrogen donor functionalised imidazolium salts have been synthesised.

Comparison of Heck C-C coupling activity of several of the palladium (II) complexes showed that substitution on the nitrogen donor effected coupling activity of aryl bromides: for bidentate ligands, an electron withdrawing group increased activity more than increasing chelate ring size; for tridentate ligands the exchange of nitrogen to carbon donor did not effect catalytic activity.

The following novel mixed nitrogen based compounds have been prepared o-(cy-imm)-ani; o-(^tBu-imm)-N-TMS-ani; o-(cy-imm)-N-(TMS)ani; Li o-(^tBu-imm)-N-(TMS)anilide; o-(^tBu-imm)-N-(3,5-dimethylphenyl)ani; N,N’-Bis-(2-amino-benzylidene)-cy-1,2-diamine; where ani = aniline, imm = iminomethyl, cy = cyclohexyl, TMS = trimethylsilyl. Transaminations of o-(^tBu-imm)-N-TMS-ani with Zr(NMe₂)₂C1₂THF₂ gave a functionalised amidinato complex and o-(^tBu-imm)-N-ani with Ti(NMe₂)₂C1₂ gave a Ti macrocyclic complex.