Investigations on the synthesis and reactivity of σ³λ³-oxaphosphirane complexes with fluorinated C-substituents

Abstract

The objective of this PhD work was to synthesize new oxaphosphirane complexes having the triphenylmethyl group bound to phosphorus. These derivatives may possess a higher lability of the P-C exocyclic bond than other derivatives, thus acting as a functional group, which should be studied in detail.<br /> A further major objective was a comparative study of the effects of electron- withdrawing groups at the ring carbon atom on the reactivity using derivatives bearing three different bulky substitutents at phosphorus: triphenylmethyl, pentamethyl- cyclopentadienyl (C5Me5) and bis(trimethylsilyl)methyl (CH(SiMe3)2).<br /> In particular, the reactivity of these novel oxaphosphirane complexes was to be investigated towards strong σ-donors i.e. N-heterocyclic carbenes, ring-opening reactions with Brønsted acids as well as SET (single electron transfer) and multiple electron reductions.