Triflyl azide

To complete the synthesis of the diazofluorene, the cyclization product 126 is treated with diisopropylethylamine and triflyl azide [50], to afford the diazofluorene 127 in 81 % yield. Under these conditions, the hydroxyfulvene is likely deprotonated to generate a cyclopentadienyl anion. Attack of this anion on the trifyl azide reagent... 

Aryl azides (such as 13) can be easily prepared from their corresponding amines (12) in one or two steps. Three examples are given in Scheme 2a. The most common method is the diazotization of the amine with sodium nitrite under acidic conditions (giving diazonium species 14), followed by addition of sodium azide in an aqueous medium (route i in Scheme 2a) [44], In 2003, the synthetic method was improved by application of triflyl azide (TfN3), which allowed a one-step conversion and gave improved yields (route ii in Scheme 2a) [45]. Recently, the development of sulfonyl azides 15 (with R = imidazole [46] or R = benzotriazole [47]) was reported these proved to be more stable reagents and allowed a conversion under mild conditions (route iii in Scheme 2a). 

Scheme 2 Preparation and examples of aryl azides, (a) Three possible routes for the conversion of an aryl amine into its aryl azide (i) via diazotization [44], (ii) by the use of triflyl azide [45], and (iii) with sulfonyl azides 15 (R = imidazole [46] or R = benzotriazole [55]). (b) Examples of substituted aryl azides...

To a soln of amino acid (0.012 mol) in sufficient 1 M NaOH to adjust the pH to 9.5, triflyl azide in CH2CI2 (ca. 1 M, 1 equiv) was added and the mixture was stirred at rt, with occasional addition of 1 M NaOH to maintain pH 9-9.5. After overnight stirring, the phases were separated, and the organic phase... 

To H-Ala-OEt (5.73 g, 49 mmol) in CH2CI2 (10 mL), triflyl azide in CH2CI2 (ca. 1 M, 1 equiv) was added along with a catalytic amount (ca. 0.1 mmol) of methyltrioctylammonium chloride, and the soln was stirred at rt for 10-15 h. The mixture was washed with 0.25 M citric acid (2 x 30 mL), the CH2CI2 layer was dried (Na2S04) and concentrated and the azido ester distilled at reduced pressure yield 4.32 g (62%). 

A versatile stereoselective synthesis of endo,exo-furofuranones was accomplished by R.C.D. Brown and coworkers. One of the key steps was a Rh(ll)-catalyzed C-H insertion reaction and the required diazo lactone was prepared via the Regitz diazo transfer reaction. The 2-acetyl substituted lactone substrate proved to be recalcitrant toward the deacylative diazo transfer under standard conditions. Eventually the authors decided to use the very reactive triflyl azide (TfNs), which was generated in situ under phase-transfer conditions to afford the desired a-diazo lactone. The C-H insertion product was then converted to (+)-methylxanthoxylol. 

The natural product (-)-oxetanocin is an unprecedented oxetanosyl-A/-glycoside that inhibits the in vitro replication of human immunodeficiency virus (HIV). In order to prepare multigram quantities of the compound, D.W. Norbeck et al. devised a short and efficient synthetic strategy. The cornerstone of the strategy was the Wolff rearrangement of a five-membered diazo ketone. The diazo transfer was achieved by first converting the ketone to an enamino ketone followed by treatment with triflyl azide. Upon irradiation with a 450 W Pyrex filtered Hanovia lamp, the isomeric oxetanes (a 3 = 2 1) were obtained in 36% yield. 

Work on the use of trifluoromethanesulphonyl azide (triflyl azide) as a reagent in organic chemistry has been initiated. Generated in situ from the anhydride (CF3-SOa)sO and sodium azide in H30-CH Cl2, it effects direct conversion of n-hexylamine, 2,4,4-trimethylpent-2-ylamine, and t-butylamine into the corresponding alkyl azides. "... 

Another advantage of sterically demanding trisyl azide is the selective azidation of cyclic 8-ketoesters (eq 32). Thus, the desired azidation product A was slowly formed as a single product in either THF or MeCN. In contrast, more reactive sulfonyl azides such as 4-methoxybenzenesulfonyl azide, 4-nitrobenzenesulfonyl azide, mesyl azide, triflyl azide, and tosyl azide provided not only the azidation product A but also a ring-contraction product B, a ring-opened diazo-transfer product C, and a mixture of ring-opened olefins D. The amounts of by-products B, C, and D were dependent upon the azide reagent. 

A. Titz, Z. Radic, O. Schwardt and B. Ernst, A safe and convenient method for the preparation of triflyl azide, and its use in diazo transfer reactions to... 

In the case of triflyl azide, the recommendation has been made that the compound not be allowed to be completely free of solvent and that it not be stored for any length of time [4], Ethyl azidoformate could be distilled at about 100°C. It did not detonate until 160°C. On the other hand, the vapors of this azide are toxic, leading to vertigo, severe headaches, and sometimes vomiting [5]. 

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