Chalcogen-Transfer Rearrangement: Exploring Inter- versus Intramolecular P-P Bond Activation

tert-Butyl-substituted diphospha[2]ferrocenophane has been used as a stereochemically confined diphosphane to explore the addition of O, S, Se and Te. Although the diphosphanylchalcogane has been obtained for tellurium, all other chalcogens give diphosphane monochalcogenides. The latter transform via chalcogen-transfer rearrangement to the corresponding diphosphanylchalcoganes upon heating. The kinetics of this rearrangement has been followed with NMR spectroscopy supported by DFT calculations. Intermediates during rearrangement point to a disproportionation/synproportionation mechanism for the S and Se derivatives. Cyclic voltammetry together with DFT studies indicate ferrocene-centred oxidation for most of the compounds presented.

Automated summary

Stereochemically confined tert-butyl-substituted diphospha[2]ferrocenophane has been used to explore the addition of O, S, Se and Te, revealing a rearrangement mechanism that has been tracked through NMR spectroscopy and DFT calculations. Experimental results show a ferrocene-centred oxidation for most compounds.