Nucleophilic addition reaction phosphinic amide

Figure 3 shows the typical synthetic route to prepare the TFSA anion based phosphonium RTILs. We have chosen triethylphosphine (P(C2Hs)3) and tii(n-bulyl)phosphine (P( -C4H9)3) as commercially available starting materials since these two phosphines can afford relatively small quaternary phosphonium cations. The preparation process of the phosphonium RTCLs includes two steps nucleophilic addition reactions of trialkylphosphines to alkyl halides to form precursor phosphonium halides and then aqueous ion exchange reactions of the precursor phosphonium halides with lithium bis(trifluoromethylsulfonyl)amide (Li-TFSA) to obtain TFSA anion based phosphonium RTBLs. 

Not only N-H bonds from amines can participate in the aminolysis reaction, but also less nucleophilic urea, thiourea and biuret NH units can react with halophosphanes in an effective manner, forming the corresponding phosphinous amides with additional functionalities at the nitrogen atom [39-44]. 

The other approach to P-ylides based on the nucleophilic addition of phosphorus(HI) reagents to the terminal carbon atom of 1,2-diaza-1,3-butadienes has continued to find application. The reaction with dialkyl-phosphonites or phosphorus(III) amides under solvent-free conditions (and in the presence of atmospheric moisture) was found to be a convenient approach to a-phosphanylidene hydrazones (42). The linear ylides (42) in THF solution undergo further intramolecular transformations to give 1,2,3X -diazaphospholes (43) in the case of phenylphosphinite as a starting substrate or 5-oxo-4-phosphoranyidene-4,5-dihydro-l/f-pyrazoles (44) using tris(dialkylamino)phosphine. 

Many of these reactions are reversible, and for the stronger nucleophiles they usually proceed the fastest. Typical examples are the addition of ammonia, amines, phosphines, and bisulfite. Alkaline conditions permit the addition of mercaptans, sulfides, ketones, nitroalkanes, and alcohols to acrylamide. Good examples of alcohol reactions are those involving polymeric alcohols such as poly(vinyl alcohol), cellulose, and starch. The alkaline conditions employed with these reactions result in partial hydrolysis of the amide, yielding mixed carbamojdethyl and carboxyethyl products. 

Hydroamination of olefins is also possible with gold catalysts. In this reaction, the attack comes Ifom a nitrogen nucleophile as a carbamate,a urea, an amide, or a sulfonamide. In the latter case, the reaction can be carried out intermolecularly. While the carbamates, ureas, and amides give only products of intramolecular anunations, the sulfonamides can perform the intermolecular addition. Only the addition of ureas (equation 146) takes place at room temperature, and in the rest of the additions heating is required. The catalysts of choice in all these reactions are cationic gold(I)-species stabilized by phosphines or NHC ligands. The reaction times have been reduced by the use of microwave irradiation. The mechanism of the hydroamination reaction has been studied in detail theoretically. ... 

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