Phosphonium compounds, amino

Certain alkylated ammonium, phosphonium, or sulfonium compounds are effective, in relatively low concentrations, in interfering with the growth of gas hydrate crystals [972] and therefore are useful in inhibiting plugging by gas hydrates in conduits containing low-boiling hydrocarbons and water. For example, tetrabutylammonium bromide will be active. Gas hydrate or ice formation is further inhibited in lines by adding amino acids or amino alcohols [523]. 

Synthesis of the amino-triazole derivative (43) was performed in the authors laboratory by Pati et al. [52] (Scheme 7). Substituted benzyl bromide was reacted with triphenylphosphine to produce the phosphonium bromide starting material, 44. The Wittig reagent, obtained by treatment with sodium hydride, was reacted with 3,4,5-trimethoxybenzaldehyde 18 to generate the nitro-stilbene 45 in good yields. The alkyne 46 was obtained by bromination of the stilbene, followed by didehydrobromination. Compound 46 was then reacted under thermal conditions with benzyl azides... 

The ring closure of amino alcohols with C02 to yield cyclic carbamates, was achieved under mild conditions (atmospheric pressure of C02, room temperature), in acetonitrile as solvent and in the presence of triethylamine as the base, using more easily available reactants, such as P(III)-derivatives (Ph3P, (PhO)3P, n-Bu3P, (MeO)3P) and haloalkanes (CC14, CC13CC13) [76]. According to the proposed mechanism, the active species is a phosphonium adduct of the used P(III)-compound with the haloalkane, which activates the intermediate carbamate formed from amino alcohol and C02 at the carbamic moiety to produce a transient species which cyclizes to the final product (Scheme 6.12). 

Unlike phosphonium salts, the uronium/guanidinium compounds may react with amino groups under the conditions commonly employed in peptide synthesis, forming guanidino-type side products (Scheme 5). 

The N-phosphonium salts of pyridines given by the oxidation of phosphorous acid and its esters are very reactive to nucleophiles, activating carboxy, amino, or hydroxy compounds to yield the corresponding carboxylic amides and esters in high yields on further aminolysis, alcoholysis, and acidolysis2 ... 

Full n.m.r. data have been obtained for the aminophosphines Pr NHPR2 (R = Ph or QF5) and the amino-phosphonium salts derived therefroma feature of these spectra is the solvent dependence of the amino-proton resonances. The new bis- and tris-(diflurorophosphino)amines (F2P)2NH and (F2P)3N have recently been prepared from gas-phase reactions of ammonia, trimethyla-mine, and PF2C1, but the compounds are difficult to obtain pure. 

ILs can be arbitrarily defined as non-corrosive molten salts that are fluid at temperatures below 100 °G. The vast majority of these compounds are based in cations of tetraalkyl ammonium and phosphonium salts and heteroaromatics (Figure 1), typically associated with inorganic and organic anions such as BF4, PF6, N(GF3S02)2, GF3SO3, RGO2, NO3, GIO4, amino-acids, MX . 

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