Accessing the First nido-Carborane-Substituted Diphosphetane: A Ligand and Synthon for nido-Carboranylphosphanes

Deboronation of a carborane-substituted diphosphetane 2 in toluene yielded the first nido-carboranyldiphosphetane 1. The P-P bond in 1 can be broken via dismutation reactions with diaryl dichalcogenides yielding nido-carboranyl bis-phosphanes that were not accessible via established synthetic protocols. Additionally, transition metal complexes of 1 could be isolated including one coordination polymer. Notably, when the deboronation of 2 is carried out in ethanol, unprecedented nido-carborane-substituted secondary bis-phosphane monoxides (3, 4) are obtained. These compounds are interesting starting materials for further reactivity studies due to their P-H bonds. Experimental findings are supported by DFT calculations including the calculation of reaction mechanisms and NMR spectroscopic parameters.