Reactivity of Aromatic Phosphorus Heterocycles - Differences Between Nonfunctionalized and Pyridyl-Substituted 2,4,6-Triarylphosphinines

摘要

Detailed studies on the reactivity of 2-(2-pyridyl)-4,6-diphenylphosphinine (2) towards CF3SO3H and sulfur have been performed, and the results were compared with those for nonfunctionalized 2,4,6-triphenylphosphinine derivatives. Substantial differences between these heterocycles were observed, and the reaction products could be characterized crystallographically. The reactions of 2,4,6-triarylphosphinine sulfides with methanol led to different products, which could be characterized by NMR spectroscopy and X-ray crystal structure analysis. Interestingly, the outcomes of these transformations strongly depend on the presence of an additional donor functionality within the phosphorus heterocycle as well as the nature of the solvent and the reaction temperature. DFT calculations were performed to rationalize the different reaction pathways.