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Azidation Using Hypervalent Iodine Compounds

Hypervalent iodine compounds represent a nsefiil source of azidyl radicals. For instance, a mixture of iodosyl benzene (PhIO), acetic acid, and sodium azide is employed for the diazidation of several olefins. A carbocationic mechanism has been proposed bnt azidyl radicals are likely responsible for the observed reactivity.  [Pg.243]

Under the optimized reaction conditions, diazidation of cyclic silyl enol ethers can be performed in good yields and generally high diastereoselectivilies. The isolated diazides also are usefnl intermediates in the way to more elaborated compounds. For instance. [Pg.243]


Tsarevsky has found that hypervalent iodine compounds can be used for the direct azidation of polystyrene and consecutive click-type functionalization [49]. In particular, polystyrene can be directly azidated in 1,2-dichloroethane or chlorobenzene using a combination of trimethylsilyl azide and (diacetoxyiodo)benzene. 2D NMR HMBC spectra indicate that the azido groups are attached to the polymer backbone and also possibly to the aryl pendant groups. Approximately one in every 11 styrene units can be modified by using a ratio of PhI(OAc)2 to trimethylsilyl azide to styrene units of 1 2.1 1 at 0 °C for 4 h followed by heating to 50 °C for 2 h in chlorobenzene. The azidated polymers have been further used as backbone precursors in the synthesis of polymeric brushes with hydrophilic side chains via a copper-catalyzed click reaction with poly(ethylene oxide) monomethyl ether 4-pentynoate [49],... [Pg.431]


See other pages where Azidation Using Hypervalent Iodine Compounds is mentioned: [Pg.243]    [Pg.243]    [Pg.138]    [Pg.278]    [Pg.155]    [Pg.120]    [Pg.14]    [Pg.393]    [Pg.260]    [Pg.15]    [Pg.194]    [Pg.246]    [Pg.531]    [Pg.31]    [Pg.130]   


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Azides compounds

Hypervalence

Hypervalency

Hypervalent

Hypervalent iodine compounds

Iodinated compounds

Iodination using

Iodine azide

Iodine compounds

Iodine compounds using

Iodine, hypervalent

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