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UBC Theses and Dissertations

Hemilabile heteroelement based ligands for early transition metal complexes, fundamental studies and applications to catalysis Thibault, Bagnol

Abstract

This thesis details the development of new hemilabile ligands using heteroelement chemistry to develop new precatalyst for hydrofunctionalization chemistry. These chelating molecules are studied with early transition metals from group 4 and 5 as titanium, zirconium and tantalum. Synthesis of 1,3-N,O-chelating complexes containing boron atom have been synthesized using a new synthetic pathway based on electrophilic Friedel-Crafts reaction that involves amineborane complexes. Coordination chemistry with titanium is studied and shows unexpected reactivity with formation of another product. 1,3-N,N-chelating complexes containing boron were investigated through two different aspects, either using cyclic or acyclic boraamidines. A four step synthesis involving subsequent borylation and Suzuki-Miyaura cross-coupling reactions is developed, to obtain cyclic boraamidine. Acyclic boraamidines were synthesized using procedures from the literature. Coordination chemistry involving early transition metals was carried out, and catalytic hydroaminoalkylation examined. Complementary to this work, another synthetic approach on order to obtain beta-aminophosphine ligands was looked at. Hydroamination of alkynes has been reported several times in the literature using either aryl or alkyl alkynes. Besides, alkynes containing heteroelements such as phosphorus remains evasive. N,P,N-type ligands were synthesized and protonolysis reactions were carried out to achieve the formation of new N,P,N-metal complexes containing early transition metals like titanium and zirconium.

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Attribution-NonCommercial-NoDerivatives 4.0 International