DBU-mediated Direct P-N Cross-coupling Of P(O)-H Compounds And N-haloimides

Phosphoramidates compounds are key structural units in a number of biologically active natural products and are widely used in the pharmaceutical industry. They not only are important chiral auxiliaries for asymmetric synthesis, but also display certain flame retardant performance. Therefore, considering the importance of phosphoramidates compounds, their synthetic methods have also been received much concern.This paper explored a kind of mild conditions, simple, safe and efficient method for the synthesis of phosphorimide compounds. Under the condition of ice water bath, we set off from P (O)-H compounds, DBU as a activator, and N-haloimides itself or plus amine as a source of amine, rapidly and efficiently to synthesize a series of phosphorimide compounds. The optimal reaction conditions were as follows:1 equiv P (O)-H compounds,1.5 equiv N-haloimides,1.5 equiv DBU, acetonitrile as the solvent and reaction in the ice water bath. The structure of the products were characterized by 1H NMR?13C NMR?31P NMR, MS and single crystal X-ray diffraction. The reaction featured broad phosphorous compounds scope, including H-phosphinates, H-phosphonates and H-phosphine oxides, relatively high yield (52-87%) and short reaction time (less than 10 min).Compared with some traditional synthesis methods, this method provides a kind of convenient, rapid and efficient route towards phosphorimides compounds. Not only the scope of P(O)-H substrates is broad, but also inherent N-haloimides or external amine can be used the nitrogen source. The P-N cross-coupling reaction has made further attempt in the way of using N-haloimides itself as a source of amine.