Stereoselective umpolung tandem addition of heteroatoms to phenol.
Upon coordination to {TpW(PMe3)(NO)}, phenol tautomerizes to a cyclohexadienone (a 2H-phenol). The uncoordinated, nonaromatic double bond of this ligand undergoes stepwise addition of electrophiles followed by nucleophiles to produce 4,5-disubstituted cyclohexenone complexes. The metal stabilizes the intermediate cationic ligand and sterically blocks one face of the ligand, resulting in a high degree of stereo- and regiocontrol. These substituted cyclohexenones are readily liberated from the metal by oxidative decomplexation.
Todd
Michael A
MA
Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, USA.
Sabat
Michal
M
Myers
William H
WH
Smith
Timothy M
TM
Harman
W Dean
WD