INVESTIGATIONS INTO RARE 3-COORDINATE PALLADIUM COMPLEXES AND NEW APPLICATIONS OF COPPER IN COUPLING REACTIONS

Abstract

In this thesis, the paper is divided into 2 parts, each corresponding to 2 individual projects. We started with looking into the synthesis of 3-coordinate palladium complexes incorporating a nacnac ligated system for academic interest. We utilized [{2,6-iPr2Ph)2nacnac}PdCl]2 as the precursor into synthesizing these 3-coordinate palladium complexes. Through many failed attempts of manipulating different substrates, we were able to synthesize a 4-coordinate [{(2,6-iPr2Ph)2nacnacPdCl}(NH2Ph)].

The second project deals with the application of dibromobis(1,1'-dibenzyl-3,3'-methylenediimidazolin-2,2'-diylidene)dicopper(I) complex to catalysis. We decided to focus our attentions specifically on carbonyl reduction of ketones being that hydrosilations with copper catalysts have only been recently looked at. The dibromobis(1,1'-dibenzyl-3,3'-methylenediimidazolin-2,2'-diylidene)dicopper(I) complex proved to be very effective at hydrosilations of a wide variety of ketones at high temperatures. We further investigated the scope of the dibromobis(1,1'-dibenzyl-3,3'-methylenediimidazolin-2,2'-diylidene)dicopper(I) catalyst by testing it on the arylation and alkylation of imidazole. The arylation of imidazole showed little to no conversion, whereas the alkylation proved to be quite active for both alkyl bromides and chlorides. We also looked at the attempts in synthesizing bulkier analogues of dibromobis(1,1'-dibenzyl-3,3'-methylenediimidazolin-2,2'-diylidene)dicopper(I) by varying the benzyl groups to 2,6-diisopropylphenyl and mesityl groups. However, results show that there were difficulties in coordinating these bulkier ligands onto copper. Optimization of complexing bulkier ligands onto copper needs to be conducted before one can proceed onto further reactions.