Radical Reactions Using Supported Reagents

Several other types of polymer-bound stannanes have since been reported, including a polymer-bound distannane used in radical-mediated cyclizations and radical addition to acetylenes [87], and stannanes with longer tethers to the polymer [88, 89] applied in the Barton-McCombie deoxygenation of alcohols [90, 91] and 

In summary, polymer-bound reagents for nucleophilic, electrophilic and radical reactions can in many instances be seen as more practical alternatives to the corresponding reaction using soluble reagents, facilitating removal of by-products in 

PSPBP polystyrene-supported pyridinium bromide perbromide 

1 Kirschning, A., Monenschein, H. and Wittenberg, R. (2001) Angewandle Chemie-International Edition in English, 40, 650-79. 

8 Carpino, LA., Williams, J.R. and Lopusinski, A. (1978) Journal of the Chemical Society D-Chemical Communications, 450-1. 

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Allyltin reagents supported on polymer underwent free radical allylic transfer with a marked preference for electron-poor carbon radicals598. The fluorous method developed by Curran and coworkers has recently been successfully extended to four-component radical reactions using fluorinated allyltin reagents599. 

The Anelli oxidation of alcohols to aldehydes and ketones has been accomplished using polymer-supported nitroxyl radical catalysts. The practicality of removing polymer-supported reagents by filtration to simplify product purification is highlighted by these examples. Bolm and coworkers11 demonstrated that a silica-supported nitroxyl catalyst is easily filtrated after use from the reaction solution, recovered and recycled, and the residual inorganic salts present in the reaction mixture are separated from the organic product by aqueous extraction (Table II, entry 7). 

Based on the data obtained, make an electrochemical model Use an electrode instead of a donor or an acceptor, and employ solutions containing a supporting electrolyte, another reagent (an acceptor or a donor, correspondingly), and stable products that this reagent produces as a result of the ion radical reaction. 

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