Phosphoramidates phosphorylation

Imidodiphosphoric acid Diamidophoaphoric acid Phosphoramide [phosphoryl amide or phosphorus (V) oxytriamide] Phosphorus 0X3Uiitride (phosphoryl nitride)... 

Compound (1) phosphorylates phosphate monoesters and alcohols, although with the latter a considerable excess of alcohol is necessary to obtain satisfactory yields. In the absence of mercuric ions the milder phosphorylating species (3) can be isolated which converts monoalkyl phosphates to pyrophosphate diesters in good yield but does not react appreciably with alcohols unless catalytic amounts of boron trifluoride are added. Amine salts of (3) are converted to phosphoramidates on heating. In the presence of silver ions, O-esters of thiophosphoric acid behave as phosphorylating agents and a very mild and convenient procedure suitable for preparing labile unsymmetrical pyrophosphate diesters, such as the... 

As mentioned in last year s Report, aromatic phosphoramidates have been used to protect 5 -phosphoryl groups in the stepwise synthesis of oligodeoxyribonucleotides. The appropriate monomer units are coupled with DCC and the phosphoramidate protecting group is removed when required with isoamyl nitrite. A rapid and general preparative method for oligonucleotides has been developed based on phosphoramidates of the highly lipophilic 4-aminophenyltriphenylmethane (25). Purification of... 

The phosphoramidic chloride (11) has been employed to phosphorylate phenols and alcohols, including carbohydrates.16 Other activity in phosphorylation chemistry has been mostly concentrated in two main areas. In the first of these, Japanese workers have continued their studies on the use of 2-substituted-4-nitrophenyl-phosphoric acids. The 7V-protonated form of the 2-dimethylamino-compound (12 R = Me) is a better phosphorylating agent than the corresponding 2-diethylamino-compound. The reaction of (12) with hydroxy-amines results in selective O-phos-... 

In 2006, Yamamoto and Nakashima picked np on this and designed a chiral A -triflyl phosphoramide as a stronger Brpnsted acid catalyst than the phosphoric acids based on this concept. In their seminal report, they disclosed the preparation of new chiral BINOL-derived A -triflyl phosphoramides and their application to the asymmetric Diels-Alder (DA) reaction of a,p-unsaturated ketones with sily-loxydienes [83], As depicted in Scheme 59, chiral A-triflyl phosphoramides of the general type 4 are readily synthesized from the corresponding optically active 3,3 -substituted BINOL derivatives 142 through a phosphorylation/amidation route. 

Acid fluorides can be used for a elean preparation of amides.9 96 The use of silylated amines is an elegant alternative, sinee liberated fluoride progressively desilylates them to more nucleophilic species. The reaction has to be started with a catalytic amount of fluoride (TBAF).92 Stannyl amines97 or phosphoryl amines (phosphoramides)98 have been used in similar reactions. 

As discussed briefly in Section I,A, glucose-6-phosphatase is now known to be a multifunctional enzyme capable of catalyzing potent phosphotransferase as well as phosphohydrolase reactions [see Eqs. (1)—(4) ]. Compounds demonstrated to function as effective phosphoryl donors include fructose-6-P (30), mannose-6-P (40), PPi (35-38), a variety of nucleosidetriphosphates and nucleosidediphosphates—most effectively CTP, CDP, deoxy-CTP, ATP, ADP, GTP, GDP, and ITP (41, 45)— carbamyl-P (43), phosphoramidate (44), phosphopyruvate (42, 43) and glucose-6-P itself (30, 31). The various phosphoryl donors are also hydrolyzed by action of the enzyme (see preceding references). Eqqa-tions (1)—(4), which describe these various activities, are given in Section I,A. 

Generally similar approaches have been employed more recently to establish the additional involvement of phosphoramidate (44) and carbamyl-P (42, 43) as phosphoryl donors and of glycerol (65) as a phosphoryl acceptor. 

A Km value of 2.8 mM for phosphoramidate serving as a phosphoryl donor with untreated rat liver microsomes has been observed at pH 6.5 by Parvin and Smith (44), who also reported values of approximately 0.45 for the ratio of phosphoramidate-glucose phosphotransferase/PPi-glucose phosphotransferase with both rat liver and kidney microsomes. The latter assays were carried out at pH 6.5 with 0.4 M glucose and 20 mM phosphate substrates. 

The thermolytic behavior of triazolines formed by the addition of phosphoryl azides to norbornenes differs from related compounds imines (phosphoramidates) are the sole decomposition products.105,466,477,478 The rate of decomposition is described by two consecutive first-order reactions, formation of the betaine in the first step and nitrogen expulsion in the... 

The reaction of phosphoryl chloride with cellulose in the presence of a nonaque-ous solvent such as carbon tetrachloride or pyridine and subsequent reaction with ammonia to form a cellulose phosphoramide (9). 

Different OP compounds have structural similarities within classes. The phosphorus compounds have the characteristic phosphoryl bond, P=0. Most OP compounds have a phosphoryl bond or a thiophosphoryl bond (P=S). All OP compounds are esters of phosphorus with varying combinations of oxygen, carbon, sulfur, and nitrogen attached. These are classified as (1) phosphates (2) phos-phonates (3) phosphorothioates (4) phosphorodithioates (5) phosphorothiolates and (6) phosphoramidates. Further, the OP compounds are categorized as (1) aliphatic (2) phenyl and (3) heterocyclic derivatives. The aliphatic are carbon chainlike in structure. TEPP, which was used in agriculture for the first time in 1946, is a member of this group. Others include malathion, trichlorfon, monocrotophos, dimethoate, oxydemetonmethyl, dimethoate, dicrotophos, disulfoton, dichlorvos, mevinphos, methamidophos, and acephate. 

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