The deoxygenation of phosphoryl (P=O) species featuring a P-heteroatom single bond (P-N or P-O) is difficult to achieve. With common reductants (e.g. LAH or silane) there is often concomitant loss of the more reactive P-N or, especially, P-O single bond.  Until our recent work, no useful method for such transformations had been reported.1 Shown in figure 1 is a convenient method for the reduction of aminophosphine oxides. The product from this one-pot reaction, an aminophosphine borane, is air and moisture stable and can easily be deprotected to give the free P(III) aminophosphine.  For a number of reasons method A cannot be used in the deoxygenation of phosphinates (P-O single bond). And so, a different technique, which also employs borohydride as a mild reductant, was developed to achieve this apparently impossible reaction �breaking P=O while leaving P�O intact (figure 2). 

Aminophosphine oxide and phosphinate reduction with LiBH<sub>4</sub>: An apparently impossible reaction, cleaving P=O while leaving P�O intact

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.

Aminophosphine oxide and phosphinate reduction with LiBH4: An apparently impossible reaction, cleaving P=O while leaving P�O intact

Aminophosphine oxide and phosphinate reduction with LiBH₄: An apparently impossible reaction, cleaving P=O while leaving P�O intact