Chemoselective Transformations of Cyclic β-Bromoacrylic Acids with Palladacycles Formed by Aryl Iodides to Access Fused or Spiro Polycycles.

A palladium-catalyzed chemoselective decarboxylative annulation of different aryl iodides with cyclic β-bromoacrylic acids for the construction of interesting fused and spiro polycycles is disclosed. Notably, cyclic β-bromoacrylic acids can chemoselectively act as C1 or C2 insertion units by the use of different aryl iodides. 2-Iodo--methacryloylbenzamides can undergo a Heck/[4+2] annulation to afford hexahydrodibenzoisoquinoline-4,6(5)-diones. Employing 2-iodobiphenyls or -(2-iodophenyl)-2-phenylacrylamides as substrates enables the assembly of spirofluorenes and dispirooxindoles.