A Grob-type fragmentation of oxonium ylide generated from intramolecular addition of oxygen to α-imino rhodium carbene was realized. The reaction was stereospecific and produced two remote double bonds. The newly...
Rh(ii)/Phosphoric Acid co-catalyzed muti-component annulation was well established as a new efficient route to construct 1-amino-indole derivatives via dearomatization/rearomatization/cyclization process with in situ formed oxonium ylide.
In contrast to prior evidence for a homolytic mechanism, a cyclopropylcarbinyl-substituted oxonium ylide furnished cleavage products consistent with a zwitterionic intermediate.