Phosphorous triamides

Acryhc esters dimerize to give the 2-methylene glutaric acid esters catalyzed by tertiary organic phosphines (37) or organic phosphorous triamides, phosphonous diamides, or phosphinous amides (38). Yields of 75—80% dimer, together with 15—20% trimer, are obtained. Reaction conditions can be varied to obtain high yields of trimer, tetramer, and other polymers. 

Hexametbylpbosphorous triamide (HMPT) [1608-26-0] M 163.2, m 7.2°, b 49-51°/12mm, 162-164°/12mm, d 0.989, n 1.466. It may contain more than 1% of phosphoric triamide. The yellow oil is first distd at atm press then under reduced press and stored under N2. It is air sensitive, TOXIC, should not be inhaled and is absorbed through the skin. [Mark Org Synth Coll Vol V 602 1973.]... 

Phosphorane (dichloromethylene) TRIPHENYL 1, 46, 33 Phosphorous triamide, hexamethyl, 46, 42... 

Phosphomum, 2-octadccenyltriphenyl, iodide [57620-98-l],81 Phosphomum, 2-octenyltnphenyl-, iodide [57620-97-0],81 Phosphonc acid [7664-38-2], 100 Phosphoric triamide, hexamethyl-... 

Hydroxymethylene formation proceeded in the standard fashion (7 ) to give a 93% yield of 22. Carcinogenic hexamethyl-phosphoric triamide was replaced by N-methylpyrrolidone as the solvent for the condensation reaction of 22 with the bromo-butenolide 23 in the presence of excess K.CO. and gave a mixture of racemic strigol (1) (35%) and 4 -epistrigol (25) (39%), which were readily separated by chromatography on silica gel. 

Modro has synthesized a series of phosphoric triamides from P(0)C13 as outlined in Scheme 33 <2001PJC1089>. This approach was not successful in forming the thio analogue but direct condensation of P(S)C13 with the triamine 322 yielded the thiophosphoryl analogue compound 323 (Scheme 34). 

Hexamethylphosphoramide Phosphoric triamide, hexamethyl- (8,9) (680-31-9) Diisobutylaluminum hydride Aluminum, hydrodiisobutyl- (8) Aluminum, hydrobis(2-methylpropyl)- (9) (1191-15-7)... 

Hexaethylphosphorous triamide (= HEPT) Diethylamide, N,N, N"-phosphinidynetris-(8) Phosphorous triamide, hexaethyl- (8,9) (2283-11-6)... 

Phosphorous triamides, hexaalkyl, from dialkylamines and phosphorus trichloride, 46, 43... 

Intensive studies concerning the photoreductive cyclization of distinct ketones and aldehydes are made by Cossy et al. [170], They describe how bicyclic tertiary cycloalkanols 173 and 174 can be prepared from, s-un-saturated ketones 172 in good yields, initiated by photoinduced electron transfer from triethylamine in acetonitrile or by photoionization in pure hexamethyl-phosphoric triamide (HMPA) [171, 172], The reaction is stereo-, chemo- and... 

Scheme 25). l-Oxo-2,8-diphenyl-2,5,8 triaza-1 X -phosphabicyclo[3.3.0]octane (68) formed by acid catalysis of the bicyclic phosphoric triamide (67) has been found to isomerize via a new type of rearrangement to yield the ring contracted 3-[2-(phenylamino)ethyl]-2-oxo-2-ethoxy-l-phenyl-l,3,2 A, -diazaphospholidine (69). The rearrangement has been explained in terms of intramolecular 1,5-nucleophilic attack... 

The average metal-ligand distances, Pr—Cl =2.72 A and Pr—0=2.353 A, are shorter than those calculated by summing the ionic radii. The average P—0 bond length of 1.487 A is slightly shorter than that observed for other phosphor-triamide [1.501 for 0P(NH2)3]. The P—N (1.64 A) possesses partial -bond character. 

Synonyms HMPA HMPT HPT hexamethyl phosphoric triamide... 

Figure 2.3 Variable-temperature H NMR spectra recorded in a hexamethyl phosphoric triamide solution of 2,6-dihydroxybenzoic acid at 135, 163, 177, and 240 K. (Reproduced with permission from ref. 26.)...

For the alkylation of tnetallated acetylenes, diethyl ether and tetrahydrofuran are unsuitable solvents, unless a certain amount of dimethyl sulfoxide (DMSO) or hexamethyl-phosphoric triamide (HMPT) is added. Alkylations in liquid ammonia with higher alkyl bromides are also slow, though addition of DMSO or HMPT followed by evaporation of (pan of) the ammonia in most cases gives rise to a smooth conversion. For methods of purifying, solvents, one should consult our previous book [ I, Chapter I). 

Selective chlorination or bromination of the 5 -hydroxyl group in unprotected D-ribonucleosides has been achieved75 by treatment with thionyl chloride or thionyl bromide, respectively, in hexamethyl-phosphoric triamide at room temperature for 10-15 hours the 5 -deoxy-5 -halogeno derivatives of cytidine and adenosine have been prepared in this way. The reactions presumably occur by way of alkoxyphosphonium salts as intermediates.78... 

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