Application of an updated version of this methodology (see below) to clinical compounds in phases 1-3 and 4 (i.e. on the market) very recently demonstrated that PNPs are strongly enriched in clinical compounds. In light of this broad historical use and success, rapid access to PNPs, preferably without the need to develop multi-step complexity-generating asymmetric transformations, would be of high relevance to future medicinal chemistry and chemical biology programs.