Reversible Formation of Yttrium Planar Cyclo-P4Cluster and Its Selective Conversion: Access to Mixed PV/PIII Cyclo-P4 Units

Abstract

The development of sustainable phosphorus chemistry from P4 remains a significant challenge, particularly in achieving its selective activation and reversible functionalization. Herein, we present a rare-earth silylamido complex that enables solvent-controlling reversible P4 activation via P-C bond formation and cleavage. Utilizing a dianionic β-diketiminato ligand, we achieve the first dynamic assembly of a planar cyclo-P4 framework coordinated to rare-earth centers. In tetrahydrofuran (THF), 2 can fully release free P4 and regenerate the precursor 1. Complex 2 also exhibits high reactivity toward unsaturated small molecules, including p-tolyl isothiocyanate and carbon disulfide, affording oxidation products 3 and 4 featuring unprecedented neutral mixed PIII/PV planar cyclo-P4 units. DFT calculations indicate the regioselectivity and underlying mechanism of the functionalization process. This work constitutes the first example of reversible P-C bond formation and P4 activation under mild, non-photochemical conditions, establishing a dynamic and tunable platform for cyclo-P4 chemistry with broad implications for main-group element reactivity and ligand design.