Synthesis of nonracemic phosphonates

Recent years have witnessed a dramatic increase in interest in the preparation of nonracemic phosphonates. The result has been significant growth in the number and variety of strategies for stereocontrolled phosphonate synthesis. Much of this interest has stemmed from the potential biological activity of phosphonates, their utility as intermediates for synthesis of other nonracemic compounds, and an increasing emphasis on preparation of chiral compounds in nonracemic form. But other ingenious applications of nonracemic phosphonates also continue to appear. Recent examples include use as nonracemic ligands for transition metal catalyst, as nonracemic carbon acids for potentially enantioselective protonation of carbanions, and as part of the functional group array of unnatural ionophores. As these applications suggest, their increased availability combine with the imagination of organic chemists will continue to spur growth in the chemistry of nonracemic phosphonates.