Staudinger reaction, triphenylphosphine

The spirophosphorane (115) has been found to react with triphenylphosphine by a conventional Staudinger reaction to produce (116) with the novel X5 P-N-X4P grouping 2L ray data are available for the latter51. ... 

Early in the last century, the Nobel Prize winning chemist Hermann Staudinger discovered a reaction between phosphines and azides, which became known as the Staudinger reaction (Staudinger and Meyer, 1919). Triphenylphosphine reacts with azides to form an intermediate iminophosphorane with the release of nitrogen gas. This intermediate quickly breaks down in aqueous environments to yield triphenylphosphine oxide and a primary amine (Figure 17.17). 

The Staudinger reaction of -substituted o-azidobenzamides 83 with triphenylphosphine yields phosphazides 84 which react with isocyanates to give, unexpectedly, the corresponding 1,23-benzotriazinone derivatives 85 <00T4079>. 

Methyl 6-amino-6-deoxy-a-D-glucopyranoside derivatives 2c were synthesized in our laboratory by a somewhat different procedure [31]. 6-0-Sulfonyl or 6-bromo-6-deoxy derivatives of methyl a-o-glucopyranoside were substituted at C-6 by sodium azide. The 6-azido-6-deoxy intermediate was then treated by acyl chlorides in the presence of triphenylphosphine (Staudinger reaction) to afford amido derivatives which were finally de-O-acetylated to give 2c. The same reaction pathway allowed the preparation of 6-alkylamido-6-deoxy-D-glucopy-ranose derivatives, starting from o-glucose [31]. 

Cyclization of the furanose derivative 340 was mediated by the action of sodium hydride to afford 341 (R = Ts) in 90% yield. The amine 340 had been obtained from the azide 342 and it was later found that thermolysis of this 1,3-azido alcohol under Staudinger reaction conditions (triphenylphosphine in f-xylene) gave the azetidine 341 (R = H) directly in 99% yield <2003TL5267>. 

Isocyanates have provided one carbon atom in transformations of the general type (296) - (290). Thus, azide (343) reacts with triphenylphosphine in a Staudinger reaction giving phosphorane (344) which is then treated with isocyanates (RNCO R = benzyl or aryl) giving naphthyridines (346) (50-59% yield) via the carbodiimide (345). The cyclization (345)->(346) occurred in toluene at 160°C (92T4601). Azide (347) undergoes a similar sequence of reactions yielding a 1 1 mixture of isomeric naphthyridines (348) and (349) (44—47% yield). 

A novel structural rearrangement of pyridooxazinones to pyridodiazepinones was discovered. Staudinger reaction of pyridooxazinone 122 with triphenylphosphine in methanol afforded lactams 123 (R = H) without epimerisation. An alternative sequence was developed for obtaining the A-alkylated lactams <07OL1529>. 

By far the most common method of formation of IMPs is the Staudinger reaction.1 This is the reduction of an organic azide with triphenylphosphine (Scheme 4). It has been proven that attack of the phosphorus is at the terminal nitrogen of... 

Azides are converted into amines by the Staudinger reaction. It is a very mild azide reduction with triphenylphosphine. ... 

In the first step, the triphenylphosphine reacts with an alkyl azide to form an iminophosphorane with loss of nitrogen Staudinger reaction). In the second step, the nucleophilic nitrogen of the iminophosphorane attacks the carbonyl group to form a four-membered intermediate (oxazaphosphetane) from which the product Schiff base and the byproduct triphenylphosphine oxide are released. 

Sasaki, T., Kanematsu, K., Murata, M. Tetrazolo-azido isomerization in heteroaromatics. III. Staudinger reaction of tetrazolopyridines with triphenylphosphine. Tetrahedron 1971, 27, 5359-5366. 

Mitsunobu and Staudinger reactions. The ligand is superior triphenylphosphine because the phosphine oxide by-product is easily removed. 

A novel solid phase method for the synthesis of 2 -amino-2 -deoxynucleoside 5 -triphosphates has been developed in which the 3 -azidonucleoside precursors are first linked to support-bound triphenylphosphine as their phosphinimines 116. Following conversion into the triphosphate, the desired 2 -amino-2 -deoxy-nucleoside 5 -triphosphates are released from the support by treatment with ammonia in the Staudinger reaction. ... 

The Staudinger reaction is a mild method for the conversion of azides to amines by treating the azide with triphenylphosphine in the presence of water. The water is necessary, because the intermediate iminophosphrane is hydrolyzed to form the amine and triphenylphosphine oxide. Reviews (a) Gololobov, Y. G. Kasukhin, L. E Tetrahedron 1992, 48, 1353-1406. (b) Gololobov, Y. G. Zinnurova. 1. N. Kasukhin, L. E Tetrahedron 1981, 37,437 72. 

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... 

Aminopyridazines can be obtained in a general transformation in high yields either from azidopyridazines or tetrazolo[l,5-b]pyridazines with triphenylphosphine (Staudinger reaction). The intermediate phosphazenes can be hydrolyzed according to three methods (89S666). 

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