Phenyl azide sulfone

The few examples indicate that sulfone-stabilized carbanions should react normally with electrophilic animating reagents (Eqs. 145158 and 146465) with the caveat that free a-amino sulfones are unstable.158,465 The (3,y-unsaturated sulfone 74 is animated at the y-position (Eq. 147),250 presumably by an ene reaction. The preparation of a-tosyl azides from nitronates was shown above in Eq. 144. The scope of this reaction does not seem to have been determined. Reaction of the anions of nitrobenzyl aryl sulfones with l-oxa-2-azaspiro[2.5]octane (13a) gives nitrobenzaldehydes by cleavage of the initially formed amination products.466 Similarly, reaction of the lithium salt of benzyl phenyl sulfone with phenyl azide gives benzilydeneaniline and phenyl sulfinate.467 No reports on animations of sulfoxide-stabilized carbanions were found. 

Other less commonly used coupling reagents include EEDQ (formation of mixed carboxylic carbonic anhydrides), Bop-Cl (formation of mixed carboxylic phosphinic anhydrides [52,53]), DPPA (formation of acyl azides), DECP (formation of acyl cyanides), MSNT (formation of mixed carboxylic sulfonic anhydrides), and benzisoxazo-lium salts (generation of phenyl esters [54]). 

To a solution of (R)-N-[[3-(3-fluoro-4-morpholinyl)phenyl]-2-oxo-5-oxazolidinyl]methane sulfonate (9.05 g) in 200 mL of DMF was added 6.367 g of sodium azide, and the mixture heated at 85°C overnight. The mixture was cooled and poured into 500 mL of water and 150 mL of ethyl acetate. The aqueous layer was extracted with ethyl acetate, and the combined organic layers were dried (MgS04), and concentrated in vacuum. The brown oil of (R)-N-[[3-(3-fluoro-4-morpholinyl)phenyl)-2-oxo-5-oxazolidinyl]methyl]azide, containing some DMF, was utilized without further purification. 

Bis(trimethylsilyl)diazene (BSD), Me3Si—N=N—SiMe3, may be prepared easily by oxidation of lithium tris(trimethylsilyl)hydrazide (1) with appropriate oxidizing agents. The BSD so formed does not oxidize further to molecular nitrogen, for example with Br2, HgO, or EtOOC—N=N— COOEt. Nearly quantitative yields of BSD have been obtained by reaction of 1 with sulfonic acid azides, R S02N3 (R = phenyl or p-tolyl) in ether at -78°C (23) [Eq. (1)]. By analogy with reaction of arenesulfonic acid azides... 

DI-f e/t-BUTYL-4-HYDROXYPHENYL ) PROPIONOXY] ETHYL 4-AZI-dosulfonylcarbanilate (DTBPSC). 3- (3,5-Di-terf-butyl-4-hydroxy-phenyl)propionyl chloride (20 g, 0.7 mol) (20) and 200 mL of dry DMF containing a few drops of pyridine were placed in a 500-mL flat-bottomed flask. The solution was stirred at room temperature as 21 g (0.7 mol) of 2-hydroxyethyl-4-azidosulfonylcarbanilate (15) dissolved in 150 mL of DMF were added. After stirring at room temperature, the DMF solution was poured into ice water and the solid was collected and dried to yield 22 g (58%) of product (mp 70-75°C). It decomposed at 175°C with evolution of nitrogen. The ir spectrum contained absorption bands at 3420 cm 1 (NH), 2120 cm 1 (azide), 1735 cm"1 (ester carbonyl), 1725 cm"1 (carbamate), and 1165 cm 1 (sulfone). 

For carbon nanotubes, organosoluble PS-SWCNT nanocomposites [292] have been prepared that could be efficiently transformed to highly hydrosoluble, pH-responsive materials via direct sulfonation of the grafted PS chains [296]. In another approach, MWCNT-C H was clicked with azide-functionalized poly(glycerol methacrylate) and the final hairy MWCNTs were used for the in situ synthesis and immobilization of monodisperse 3 nm-sized palladium nanoparticles. The final heterostructure had a high catalytic activity (77%) for the C-C coupling Suzuki reaction between 4-bromobenzene and phenyl boronic acid [293],... 

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