Main text. Phosphorylation of alcohol-containing biomolecules is one of Nature's most simple methods for regulating cell circuitry. Introduction of a phosphate group can also be critical in the medicinal, 2 agrochemical, and materials areas. Biological enzymatic phosphorylation overcomes thermodynamic barriers to achieve selective functionalization through molecular recognition and by lowering the activation energy of the P-O bond forming step. Current purely chemical alcohol phosphorylation methods all suffer from various limitations and/or multistep processes (Figure ). For example, the use of P(III)-based phosphoramidites require a three step process for installation including protecting group removal and oxidation. 7 P(V)based strategies such as the use of POCl3 and derivatives thereof can be problematic due to over reactivity (often producing mixtures of mono-, di-, and tri-alkylphosphates) and protecting group manipulations. The direct use of phosphoric acid requires high temperatures and exhibits limited scope due to the high acidity and harsh conditions. Activation methods used in concert with phosphoric acid or its salts have been employed with limited scope. The recently reported bioinspired method based on an enzymatically produced P(V)-reagent (PEP-K) solves many of these problems despite requiring its use in excess at 100 °C. However, like all known methods it suffers from a lack of chemoselectivity (in this case free amines are not tolerated). The recently disclosed P(V)-based -platform for the construction of P-linkages has been applied to the simplified synthesis of an ever growing, diverse range of compounds such as: cyclic dinucleotides, stereopure anti-sense oligonucleotides, methylphosphonates, 14 chiral phosphines, 14 DNA 5 and protein bioconjugates, complex alkaloids, and fully chemically modified oligonucleotides using a commercial automated synthesizer. As part of the ongoing -platform development,  O (1) was identified as a suitable reagent for forging phosphodiester bonds. This Letter builds on those findings to highlight how the chemoselective nature of -reagents can be leveraged to access phosphates from alcohols in a mild, scalable, and operationally simple (one-pot) fashion across a wide range of alcohol substrates. Previous work on the -platform demonstrated that these reagents facilitate formation of phosphate (or thiophosphate) linkages via stepwise nucleophilic addition of two different alcohols. In a similar manner, appendage of an alcohol to the  O reagent to form intermediate -loaded adduct, followed by addition of water should in principle lead to the formation of monoalkyl phosphate. To explore the feasibility of this idea, alcohol 2 was chosen as a simple substrate to start optimization efforts (Table ). In fully optimized form, the reaction requires 1.5 equivalents of  O and DBU as lower quantities lead to diminished yield due to formation of double addition products (dialkylphosphates, Table , entry 2) or decreased conversion (Table , entry 3). Consistent with prior findings, the reaction performs best with DBU as a base although DBN and DABCO furnish product in diminished yield (Table , entries 4-8). Best conversions are achieved in anhydrous DCM although MeCN or DMF can be used with only slightly lower yields (Table , entries 9-12). Unsurprisingly, control experiments confirm the need for  O and base for initial P-O bond formation, and H2O for the hydrolysis step (Table , entries 13-15). The reaction can be performed without using anhydrous solvent and open to air, but affords the desired product with diminished yield due to competing hydrolysis of  o reagent during loading step (Table , entries 16 and 17). -Aminoalkyl dihydrogen phosphates and their salts are used as active ingredients in cosmetics, promoting fibroblast proliferation and collagen biosynthesis. They are also employed in biochemistry as linkers for bioconjugates. However, their availability is hampered by inconvenient synthetic routes. For instance, compound 5 was previously synthesized in 51% isolated yield (only melting point and elemental analysis reported) by condensation with crystalline H3PO4 at 150 °C under high vacuum (Table , entry 1). 20b Milder routes to phosphate 5 require Fmocprotection of the amine functionality, followed by phosphorylation by POCl3, and deprotection (64% over 3 steps, entry 2). 20c As it is known that  reagents are exquisitely O-selective, the chemoselectivity of the direct phosphorylation in the context of -aminoalcohol 4 was examined. We started by surveying 7 literature conditions and out of those reported protocols, six delivered little to no observable 5 with the main byproduct being both N-and Ophosphorylation as part of a complex mixture (Table , entries 3-8). Only the harsh conditions of phosphoric acid at 160 °C delivered synthetically useful yields in our hands (entry 9) likely due to the in situ protonation of the amine. In stark contrast, our newly developed conditions using 1 followed by hydrolysis cleanly provided 5 at ambient temperature (Table , entry 10). Importantly, no Nphosphorylated product could be observed by 31 P NMR.