TEMPO-mediated oxidations protocol

Anelli s protocol for the TEMPO-mediated oxidation of alcohols... 

One important limitation of TEMPO-mediated oxidations, under Anelli s conditions, originates from competing reactions produced by HOC1, generated in situ from NaOCl. This problem can be solved by the use of [bis(acetoxy)iodo]benzene (BAIB) as a secondary oxidant following the protocol of Piancatelli and Margarita27 which has proved to be particularly efficient in difficult substrates,34 and it is a highly recommended alternative to Anelli s procedure when oxidations with oxoammonium salts are desired. 

Although TEMPO-mediated oxidations under Anelli s protocol are routinely performed at a slightly basic pH of 8.6 9.8,10 obtained by buffering the bleach solution with NaHCX>3, sometimes, in order to avoid base-induced side reactions, it is advisable to adjust the pH at 6.5-7.5 by adding an acid.13 A proper adjustment of the pH for example allows to obtain carbonyl compounds without a-epimerization in difficult substrates in which other common oxidants fail.42... 

In variance with Anelli s conditions, TEMPO-mediated-oxidations—under the protocol of ... 

The very common TEMPO-mediated Anelli s protocol for the oxidation of alcohols, involving a biphasic CH2Cl2-water mixture containing catalytic TEMPO, or an analogue thereof, and sodium hypochlorite as a secondary oxidant, shows a great selectivity for the oxidation of primary alcohols in the presence of secondary ones9 and has found some use in Synthetic Organic Chemistry.10... 

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