Phosphoric acid triamides

The prototype of this class, OP(NH2)3, is formed in the reaction of OPCI3 with liquid ammonia orwith gaseous NH3 in trichloromethane solution at low temperature. Substituted phosphoric acid triamides 0=P(NR2)3 are prepared in the reaction of phosphoras oxotrichloride with secondary amines, under heating or in the presence of acid scavengers under milder conditions the mono- and diamido chlorides can be easily obtained (equation 6). Hexamethylphosphoric acid triamide, OP(NMc2)3, an excellent aprotic organic solvent prepared from OPCI3 and dimethylamine, deserves to be mentioned here. ... 

Alternative preparations for phosphoric acid triamides, QP(NR2)3, Q = O, S, include oxidative additions of tris(amino)phosphines, P(NR2)3, with oxygen and sulfur. ... 

The first attempts to control a synthetic process using multifunctional monomers were published in 1967/68 by Stille and co-workers [9-12]. They condensed 2,5-disubstituted 1,4-benzoquinones 2 with various tetra-functional aromatic compounds 1 containing amino-, hydroxy- and chloro- functionalities. When carrying out the reaction at high tanperature in polar, aprotic solvents such as HMPT (hexamethyl phosphoric acid triamide) they immediately ob-... 

Cyclic peptides 248 containing cysteine units can lose one sulfur atom by interaction with hexaethyl phosphoric acid triamide, affording ring-contracted structures 249 (83BCJ2044, 83MI2 86BCJ2505) (Scheme 67). 

Alkoxytriaminophosphonium salts Phosphinic azides Phosphoric acid triamides... 

Ester Enolates Quite different is the situation when ester enolates are used as nucleophiles. The yields obtained are generally low, and it is assumed that nonstabilized carbanions attack the metal in preference to the aUyl group [110], resulting in reduction of the complex rather than alkylation. However, addition of hexamethyl phosphoric acid triamide (HMPA) to this reaction completely suppresses the reduction and permits the alkylation to proceed with nonstabilized carbanions as well [111]. For example, treatment of tt-allylpalladium chloride with... 

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