Mono-deoxygenation of Nitroalkanes, Nitrones, and Heterocyclic N-Oxides by Hexamethyldisilane through 1,2-Elimination: Concept of “Counterattack Reagent”
摘要:
Transformation of secondary nitroalkanes to ketoximes was achieved in 40-73% yields by treatment of the corresponding nitronate anions with hexamethyldisilane. In this new mono-deoxygenation process, hexamethyldisilane acted as a "counterattack reagent". The conversion of nitrones to imines was also achieved in 82-88% yields by use of trimethylsilyllithium. Similarly, heterocyclic N-oxides were converted to the corresponding N-heterocycles in 73-86% yields. These deoxygenation processes presumably involve a 1,2-elimination.
AbstractA metal‐ and oxidant‐free, practical and efficient method for the synthesis of highly versatile and synthetically useful ortho‐trifluoromethanesulfonylated anilines from arylhydroxylamines and trifluoromethanesulfinic chloride was developed. This rapid transformation proceeded smoothly with good yields and excellent ortho‐selectivity in the absence of any metals or ligands. Mechanistically, the reaction comprised a noncanonical O‐trifluoromethanesulfinylation of the arylhydroxylamine, and the subsequent [2,3]‐sigmatropic rearrangement to afford ortho‐trifluoromethanesulfonylated aniline derivatives. The practical application of this reaction was demonstrated by further conversion into a series of functional molecules under different reaction conditions.
Yoshioka, Tadao; Yamada, Hidetoshi; Uematsu, Takayoshi, Journal of the Chemical Society. Perkin transactions I, 1985, p. 1271 - 1276