10.18453/rosdok_id00005664 Kushik http://d-nb.info/gnd/1410781852 Universität Rostock 2025 540 Chemistry & allied sciences 2025 en https://purl.uni-rostock.de/rosdok/id00005664 urn:nbn:de:gbv:28-rosdok_id00005664-5 This thesis comprises four parts. First, attempts to synthesize phosphaalumenes using phospha‑Wittig reagents and Al(I) sources revealed transient intermediates that deactivate via dimerization or C–H activation. Second, a new azide‑Wittig reaction forms triazabutadienes from azides and aldehydes under mild conditions with broad scope. Third, bis‑phosphaalkene P,N,P ligands from carbazole give strong donors. Finally, Rh(I) complexes show distinct coordination and C–H activation, expanding phospha‑Wittig chemistry.