Activation of B-interElement (E=S, Se) reagents towards selective C-S and C-Se bond formation

Identificador:  TDX:2610

Handle: https://hdl.handle.net/20.500.11797/TDX2610

Autors:  Garcia Civit, Marc

Resum:
This thesis describes the work done with reagents that contain links boron-sulphur or boron-selenium. These reagents have used in reactions of thioboration and selenoboration of substrates with unsaturation conjugated to ketones or esters and in reactions of insertion with diazo compounds to synthesize new organosulfides and organoselenides compounds. The thesis is divided in four chapters. The first is a brief introduction to the organosulfides and organoselenides compounds, reporting its main applications and its more representative methods of synthesis. The first chapter also reported the synthesis of the boron-sulphur and boron-selenium reagents and the reactions where they have been used. The second chapter is about the reactivity of the compounds of boron-sulphur with α,β-unsaturated ketones and aldehydes. It has observed that the carboxyl group is able to activate the B-S reagent and deliver the sulphur unit in the beta position. The third chapter shows the reactivity with triple bonds conjugated to ketones and esters to synthesise vinyl sulphates and vinyl selenates. The same reaction in presence of a phosphine allow to obtain anti-3,4-selenoborated compounds that they are precursors of compounds with the selenium moiety in the alpha position. The last chapter is about the insertion reactions of diazo compounds into the boron-sulphur bond that allow to obtain molecules very functionalized with groups Si, B, S and H than due to its different chemical behaviour can be further functionalized.