From activation to stabilization Different applications of a frustrated Lewis pair

This thesis describes the reactivity of geminal phosphorus/boron-based frustrated Lewis pairs in this diverse field of chemistry, including main-group catalysis, stabilization of highly reactive intermediates, and organometallic chemistry. In chapter 1 we provide an overview of p-block based compounds that facilitate the stoichiometric and substoichiometric dehydrogenation of amine-boranes. In chapter 2 we describe that our geminal FLP tBu₂PCH₂BPh₂ can dehydrogenate dimethylamine-borane in a stoichiometric fashion. We highlight that a modification of the B-substituents changes the reactivity of the FLP, resulting in a catalytic system for the acceptorless amine-borane dehydrogenation. Next, we studied the reactivity of tBu₂PCH₂BPh₂ towards phenyl, tert-butyl, mesityl, and trimethylsilyl azide (chapter 3) and we showed that this FLP can trap the “Staudinger-type” phosphazide intermediate affording a four, five or six-membered ring. Chapter 4 focuses on the use of tBu₂PCH₂BPh₂ as ambiphilic ligand for several gold(I) precursors and the difference in coordination behavior between this FLP and its P/Al analogue is described. We describe in chapter 5 the reactivity of tBu₂PCH₂BPh₂ towards copper(I) chloride. We found that the reaction of tBu₂PCH₂BPh₂ with 1 equivalent of Cu(I)Cl resulted in the formation of a chloro-bridged dimeric copper(I) complex with green luminescent properties upon UV irradiation. Finally, in chapter 6 we describe an improved method for the synthesis of diphenylchloroborane, dimesitylchloroborane and bis(pentafluorophenyl)chloroborane using a two-step procedure. We also introduced a new methodology for the selective synthesis of highly Lewis acidic diarylchloroboranes following a protection–deprotection strategy.