Kirsanov reaction

A. From Amides and Phosphorus(v) Halides.—The Kirsanov reaction remains one of the most important routes to acyclic phosphazenes some recent examples of this reaction are summarized below ... 

In some cases, the Kirsanov reaction may be modified so that an excess of the amine removes the hydrogen chloride formed ... 

Further examples of tribromophosphazenyl derivatives, which are not available from the Kirsanov reaction, have been reported ... 

This derivative readily undergoes the Kirsanov reaction and the above-noted type of reaction with thionyl chloride ... 

The Kirsanov reaction (Scheme 5) is a valuable supplement to the Staudinger reaction starting from phosphorus pentachloride and amine or amide derivatives it opens an access to P-halogenated iminophosphorane 9 (50IZV426). 

A variant of the Kirsanov reaction was developed by Zimmer et al, where the system iodine/base/triphenylphosphane was used for the preparation of iminophosphoranes (68TL3811). 

Tropon-2-ylimino)triphenylstibane, prepared by the Kirsanov reaction between Ph3SbCl2 and 2-aminotropone, undergoes a formal [8+ 2]-type electrocyclization with carbon disulfide, phenyl isocyanate, phenyl isothiocyanate, and diphenylcarbodiimide to give the corresponding cyclized products in moderate yields (Equation (35)).68... 

A less commonly employed method of preparation is the Kirsanov reaction.3 Strictly speaking, this is the reaction of phosphorus pentachloride with benzene-sulfonamide, which can be reacted further to form benzenesulfonyliminophos-phoranes. However, the name is now used generically to cover the reactions of triphenylphosphorus dihalides and amines in the presence of a base (Scheme 5). Attack of the amine on phosphorus gives the intermediate aminophosphonium salt and HBr, elimination of another equivalent of HBr generates the IMP. If the amine is aromatic, then 2 eq. of a mild base (e.g. triethylamine) are sufficient to perform the reaction in one pot.4 However, in the case of alkylamines, it is generally necessary to isolate the phosphonium salt and treat it with sodamide to effect the deprotonation and generate the IMP.5... 

Cyclophosph(V)azanes with five-coordinate phosphorus are mostly dimeric, four-membered ring derivatives, [X3PNR]2 (6). Several reviews cover the subject. A simple preparation of these compounds involves the reaction of PCI5 with primary amines (or their hydrochlorides), the so-called Kirsanov reaction. Weakly basic amines form monomeric Cl3P=NR, but with more basic amines (e.g. with R = alkyl), the products are the cyclic dimers. Various anilines give either a monomer or a cychc dimer, depending upon their basicity. ... 

From Amides and Phosphorus(v) I des.— The Kirsanov reaction has been used to advantage in the synthesis of certain P-aryl-phosphazenes ... 

Iminophosporanes (phosphazenes) are easily formed by a Staudinger reaction of azides with triphenylphosphine or a Kirsanov reaction, which is a process that takes place between an amine and dichlorotriphenylphosphorane. The ready availability of... 

The Kirsanov reaction also continues to be used to generate phosphazenes. The reaction of PCI5 with (RO)2P(0)NH2 proceeds... 

From Amides and Phosphorus(v) Halides.—Aminodifluorophosphine, FgP NHz, which was only recently reported, has been shown to undergo the Kirsanov reaction, giving an iV-phosphinophosphazene, of which there are few examples known ... 

The Kirsanov reaction continues to be useful in this regard. 

Ph2P(S)SePPh2=NSiMe3. The double Kirsanov reaction of (C 3PNMe>2 with primary aromatic amines gives the bis phosphinimine hydrochloride (RNH)2P(=NR)NP(NHR)2NHMe C . The structure observed (Section 7) has been rationalized on the basis of hyperconjugation of the NMe lone pair and the adjacent PN bond. 

Eirst systematic study of phosphate bonding and phosphate cements Kirsanov reaction discovered Identification of UDP glucose Formulated rules for base composition of DNA Advanced theories of phosphate glass structure First NMR spectra of P compounds published Showed (with P) that viruses work by injecting their DNA or RNA into cells under attack... 

The Kirsanov reaction which takes place between phosphorus pentahalides and amines of various kinds, can be used to produce monophosphazenes (3.116). 

Reaction (7.452) is the Kirsanov reaction, which was discovered in 1950 [8,9]. Both the group R and the halogenated phosphorane can be varied to produce a wide range of compounds (Figure 7.15). 

While silyl iminophosphoranes of the type R3P=N-SiRJ can be obtained by the Kirsanov reactions such as (7.459), halogen derivatives can be obtained by reaction... 

Hydrazinium di-chlorophosphazene, Cl3P=N-N=PCl3, can be made by the Kirsanov reaction (7.498). It is a colourless very hygroscopic solid which is slightly soluble in POCI3, but insoluble in other common solvents. Controlled hydrolysis at low temperature leads to unstable hydrazido-N,N-bis(phosphoryl dichloride) (7.499), but with excess water the products are HCl, H3PO4 and N2H4 (7.500). 

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