Reactivity of bulky aminophosphanes towards small molecules: Activation of dihydrogen and carbon dioxide by aminophosphane/borane frustrated Lewis pairs

Abstract

A series of mono- and bisaminophosphanes with formulas R2NPR’R’’ and (R2N)2PR’ (R = iPr, Cy; R’ = Ph, Cy; R’’ = iPr) were characterized by X-ray analysis, NMR spectroscopy and computational methods. The common structural futures of these species are short and polarized PN bonds, a pyramidal geometry at the P atom and an almost planar geometry at the N atoms. According to DFT calculations, these compounds are highly nucleophilic, with nucleophilic centers located on the N and P atoms. Except for species containing a PPh2 moiety, the obtained aminophosphanes are air-stable and do not react with water. They form stable frustrated Lewis pairs with BPh3 or B(C6F5)3. Mono- and bisaminophosphanes in the presence of B(C6F5)3 activate dihydrogen and carbon dioxide at room temperature.