Organophosphorus-Catalysed Staudinger Reduction

The first Staudinger reduction that is catalytic in phosphine has been developed, showing excellent yields and functional group selectivity. To this end we utilised dibenzophosphole catalysts and mild in situ reduction of the intermediate iminophosphoranes. We could avoid the necessity of water during the reduction, obtained no phosphine oxides as waste and thus enabled facile purification of the product. A range of azides was converted into amines with good to excellent yields and high functional group tolerance.