Iron(II)-mediated Nitrene transfer from t-butyloxycarbonyl azide (BocN3) to sulfoxides, sulfides, and ketene acetals
作者:Thorsten Bach、Christina Korber
DOI:10.1016/s0040-4039(98)00927-7
日期:1998.7
nitrene transfer from t-Butyloxycarbonyl azide (BocN3) to several nucleophiles is promoted by ferrous chloride (FeCl2) and yields the corresponding N-Boc protected sulfoximides, sulfimides, or a-amino alkanoates. Whereas the sulfoximide formation occurs spontaneously in CH2C12 as solvent the FeCl2-catalyzed nitrene transfer to sulfides and ketene acetals requires addition of a polar solvent. DMF was
The Preparation ofN-tert-Butyloxycarbonyl-(Boc-)Protected Sulfoximines and Sulfimines by an Iron(II)-Mediated Nitrene Transfer from BocN3 to Sulfoxides and Sulfides
yield). The sterospecificity of the reaction was demonstrated with the enantiomerically enriched substrates (R)-(+)-1b and (S)-(–)-1d which yielded the sulfoximides (R)-(+)-3b and (S)-(–)-3d with retention of configuration. Mechanistically, an intermediate (nitrene)FeIV complex is postulated as the reactive nitrenetransfer reagent which is formed from FeCl2 and BocN3. The more nucleophilic sulfides 2 reacted