Anion radical chain cycloaddition of tethered enones: intramolecular cyclobutanation and Diels-Alder cycloaddition.
[reaction: see text] The anion radicals of certain bis(enones), generated by cathodic reduction, are observed to participate in intramolecular cyclobutanation, yielding bicyclo[3.2.0]heptane derivatives through an anion radical chain mechanism. Evidence for stepwise cycloaddition involving distonic anion radical intermediates is presented. In addition to the novel anion radical cyclobutanations, an unprecedented intramolecular anion radical Diels-Alder product is observed. Parallel trends in substrate scope vis-à-vis the Co-catalyzed bis(enone) cyclobutanation are discussed.
Roh
Yeonsuk
Y
Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712, USA.
Jang
Hye-Young
HY
Lynch
Vincent
V
Bauld
Nathan L
NL
Krische
Michael J
MJ