Phosphorous and phosphoric acid derivatives

The reaction for R = MCjCH apparently proceeds via the formation of an acid chloride intermediate, (Me jCHO) 3P(COCl)Cl [666a]. This later work [1666] refutes that published earlier [1058] in which the product of the reaction of (MeO)3P with COClj was reported to be (MeO) jP(0)(C0Cl) (accompanied by the elimination of MeCl). Furthermore, the addition of a second molar equivalent of (MeO)3P to the product of reaction (10.43) proceeded according to Equation (10.44) [1666] rather than forming the ester of carbonylphosphinic acid, as reported previously [1058]. 

This chloroformate then either decomposes to give (PhO)2P(0)Cl and COj, or reacts with the starting material to form the corresponding pyrophosphate, (Ph0)jP(0)0P(0)(0Ph) j. Less of the phosphorochloridate is formed in the reaction of phosgene with the cyclic phosphodiester, although the mechanism is believed to follow the same general pathway [1678]. 

Aliphatic aminoesters of phosphoric (and thiophosphoric) acid react with phosgene. Equation (10.45), under milder conditions (ca. 0 C) than do the aromatic aminoesters. Only 

Diethyl esters of -alkylamino phosphoric acid react readily with phosgene. Carbon dioxide and chloroethane are liberated, reaction occurring at the phosphoryi group in preference to the nitrogen atom [508]  

Treatment of the hexamethylphosphoric triamide, hexamethylphosphoramide, (MejN)jPO, with COClj gives [(MejN)3POCOCl]Ci, which decarboxylates to [(Me2N)3PCl]Cl - an intermediate in the preparation of the peptide coupling reagent known as the BOP reagent [341,342,778], 

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Carbon-13 shifts of representative phosphines [364], phosphonium salts [365], phospho-nium ylides [365, 366], diphosphines [367], phosphonates [368], phosphorous and phosphoric acid derivatives [369] are summarized in Table 4.49. I3C shift data of some group V organoelement compounds are compared in Table 4.50. It turns out that a sp3 carbon nuclei of phosphines and arsines are shielded (0-25 ppm) relative to those of amines (30-60 ppm), as expected from the heavy atom effect, sp2 carbons of CC double bonds behave correspondingly, as shown for the triphenyl derivatives in Table 4.50, with... 

Table 4.49. 13C Chemical Shifts of Representative Phosphines [364], Phosphonium Salts [365], Phosphonium Ylides [365, 366], Diphosphines [367], Phosphonates [368], Phosphorous and Phosphoric Acid Derivatives [369] (Sc in ppm). 

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