The reaction of 2,4,6-trimethylbenzonitrile N-oxide with various di- and tetrasubstituted p-benzoquinones and the structures of the products were studied. All of the tetrasubstituted quinones gave dioxazole derivatives through addition at the carbonyl site, whereas the disubstituted quinones gave dioxazoles or isoxazoline derivatives depending on the substituents. The reactivity of the quinone carbonyl toward the nitrile oxide varies with the substituents and with the substitution pattern; this phenomenon is discussed in terms of the resonance and inductive effects of the substituents.
A Catalytic Oxidative Quinone Heterofunctionalization Method: Synthesis of Strongylophorine-26
作者:Wanwan Yu、Per Hjerrild、Kristian M. Jacobsen、Henriette N. Tobiesen、Line Clemmensen、Thomas B. Poulsen
DOI:10.1002/anie.201805580
日期:2018.7.26
functionalization with a collection of O, N, and S nucleophiles, using oxygen as the terminal oxidant. Preliminary mechanistic observations and the first synthesis of the cytotoxic natural product strongylophorine‐26 is presented.