'Alane ­ A Chemoselective Way to Reduce Phosphine Oxides'

All the work done in this paper was done by undergraduate workers either as part of their final year project (Andrew Bootle-Wilbraham) or over the summer of 1998 (James Longstaff and Steven Head). Much of the funding for this project came from Pfizer.

We demonstrated in this paper that alane (AlH₃) is a chemoselective reagent for the reduction of phosphine oxides. So, for instance, although sulfoxides themselves are reduced by alane, when a phosphine oxide is present they are left alone and the phosphine oxide is reduced instead. Impresively, chemoselectivity was demonstrated for a range of functional groups in this way ­ most of the time the phosphine oxide wins.

Alane has other advantages when it comes to the reduction of phosphine oxides. The workup procedure is particularly easy to perform and the yields are excellent. The high yields obtained are a testament to both the skill of the undergraduates involved and to the robustness of the reaction.