Ammonium hypophosphites

Two preparations of diesters of phosphonous acid have been reported, - One of these, which claims to be the first preparation of these derivatives, involves the reaction of ammonium hypophosphite with triaikylsilylamines to give bis(trialkylsilyl) esters (127) in excellent yield. These compounds are extremely reactive, e.g. they are spontaneously inflammable in air. Dialkyl phosphonites (128) have also been prepared by the reduction of... 

A synthesis of A-substituted a-aminobenzylphosphinic acids starts from ammonium hypophosphite this is allowed to react with primary amines together with aldehydes or ketones in the presence of HC1.60 The nature of the products and general success of the Atherton-Todd reaction for the preparation of dialkyl- and diaryl-phosphinic amides from secondary phosphine oxides depends on the order in which reactants are mixed and on the choice of polyhalogen reactant.61... 

Binaphthophosphepines can also be synthesized from 2,2 -bis(halomethyl)-l,T-binaphthyls 96, 101, and different phosphorus-containing compounds. Thus, the BH3 adduct 17 was obtained in good yield from 2,2 -bis(bromomethyl)-1,1 -binaphthyl 96 and ammonium hypophosphite in six steps in a good yield <2003JOC3258, 20010L2525>. 

Ammonium hypophosphite, NH4H2P02.—Evaporation of the solution obtained by mixing solutions of barium hypophosphite and ammonium sulphate yields a residue from which alcohol extracts ammonium hypophosphite, hexagonal1 laminae or rhombic2 plates, melting at 100° C. When heated above its melting-point it is converted into spontaneously inflammable phosphine, ammonia, and water. 

Ammonium hypophosphates.—Excess of ammonia converts hypo-phosphoric acid in solution into normal ammonium hypophosphite,... 

Aminoalkyl and Related Acids. Various 1-aminoalkylphosphonic acids (313) have been obtained in high yield by microwave assisted reaction of ammonium hypophosphites (314) with aldehydes (Scheme 83). ... 

Various free radical reactions at room temperature in the presence of chiral and achiral tetrasubstituted-ammonium hypophosphites in water using 0.5 equiv of Et3B-air as radical initiator. 

Jang and co-workers reported on the development of an enantioselective radical addition reaction to glyoxylate oxime ether for the preparation of a-amino acids under mild reaction conditions with chiral quaternary ammonium salts of hypophosphorous acid in aqueous media.26 The newly prepared chiral quaternary ammonium hypophosphites are inexpensive, less toxic than metal-containing compounds and the reaction conditions and workup are mild and simple (Table 7.2). It is also important to note that chiral quaternary hypo-phosphites are recyclable without altering their performance. The... 

A bent P02 group is found in ammonium hypophosphite, NH4H2P02, but this is due to the fact that the compound is not an acid salt but a neutral salt in which the radical must be more properly regarded as the tetrahedral PH202 group. This point is considered in more detail later ( 12.18). 

Ammonium Iodide, H41N, mol wt 144.96. H 2.78%, I 87.55%, N 9.66%. NH41. Contains about 98% NH4I abom L% ammonium hypophosphite is usually added as a preservative. Prepd from ammonia, iodine and hydrogen peroxide from ammonia and hydrogen iodide Or from ammonium carbonate and hydrogen iodide Wulff, Cameron, Z. Physik, Chcm. B10, 350 (1930) Schmeisser in Hand-... 

FIGURE 5.34 Crystal structure of ammonium hypophosphite (NH4H2PO2). Small open circles = H filled circles = P. (Adapted from W.H. Zachariasen and R.C.L. Mooney, J. Chem. Phys., 2, 34,1934.)... 

Trimethylsilyl phosphonite, (Me3SiO)2PH, can be obtained from ammonium hypophosphite by reaction (9.291). Some reactions of this compound are indicated in Figure 9.13 [50]. 

A typical electroless plating solution is composed of a cation provider such as nickel sulfate, a reducing agent such as ammonium hypophosphite, and additional additives tiiat help prevent the bath from decomposition, i.e., plating spontaneously. When an activated substrate is immersed in the plating bath at a temperature of 80 C and a pH around 6, nickel cation in the bath are reduced by hypophosphorous acid, and the nucleation of nickel deposition starts at the activated locations. Because nickel readily plates to itself (self-catalysis), the deposition continues and eventually fills the via locations in the dielectric with nickel metal. The reduction reaction can be expressed by the following equations ... 

When hypophosphites are heated they decompose and evolve hydrogen and phosphine. The following thermal decomposition has been assumed for ammonium hypophosphite ... 

The original publication prescribes that approximately 0.1 g of the pulverized mineral be heated for about 2 minutes in a small evaporating dish with 2 g of ammonium hypophosphite. However, the fusions are successful with even a few milligrams of the pulverized sample. The colors of the various melts and their respective indications are ... 

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