Figure 5: Experiments to elucidate the reaction mechanism and possible reaction pathways. | Nature Communications

Figure 5: Experiments to elucidate the reaction mechanism and possible reaction pathways.

From: Carbene-catalysed reductive coupling of nitrobenzyl bromides and activated ketones or imines via single-electron-transfer process

Figure 5

(a) The experiment indicates that the α-ketoester has no effect for the generation of nitrobenzyl radical. (b) The result suggest that the 1,2-addition product unlikely come from 4-nitro toluene in the current reaction system. (c) The coupling product could not be produced in the presence of NaOMe. (d) The final product could not be obtained via the alkylation of a-hydroxyl ester. (e) The result indicates that the nitro benzyl radical is existent in current reaction system. (f) The nitrobenzyl radical B2 could be formed via oxidation of Breslow intermediate A1 and leaving of bromide anion from B1. Subsequently, the carbon-carbon bond can be formed via 1,2-addition of nitrobenzyl radical intermediate B3 or ionic intermediate B5 to carbonyl compounds.

Back to article page