Catalytic Enantioselective Synthesis of 3,4,5-Trisubstituted Isoxazoline <i>N</i>
-Oxides and Regioselective Synthesis of 3,4,5-Trisubstituted Isoxazoles
作者:Subas Chandra Sahoo、Subhas Chandra Pan
DOI:10.1002/ejoc.201801693
日期:2019.2.14
A convenient catalytic asymmetric synthesis of 3,4,5‐trisubstituted isoxazoline N‐oxides and regioselective synthesis of 3,4,5‐trisubstitutedisoxazoles has been developed.
The synthesis of five-membered rings using fluoromethylene transfer chemistry is an attractive method for building fluorinated products of high value. This work demonstrates for the first time that one-fluorine-one-carbon modification of a substrate could be a viable strategy to access monofluorinated five-membered rings. The synthetic methodology was developed to access monofluorinated isoxazoline-N-oxides
A novel [4 + 1] dearomative spiroannulation of α-halo-β-naphthol and nitroolefin has been developed for the direct construction of various spiroisoxazolidines in high chemo- and diastereoselectivity. Notably, halophenols (X = Cl and I) were also tolerated by this reaction. This transformation was realized through a sequence of electrophilic dearomatization/dehalogenation, and mechanistic studies revealed