Palladium-catalyzed sequential alkylation-alkenylation reactions and their application to the synthesis of fused aromatic rings.
The synthesis of fused aromatic carbocycles from aryl iodides and difunctional acceptors is outlined. This methodology is based on a palladium-catalyzed aromatic substitution followed by an intramolecular Heck sequence. Under the optimized conditions (Pd(OAc)(2) (10 mol %), tri-2-furylphosphine (20-30 mol %), norbornene (2 equiv), Cs(2)CO(3) (2 equiv), CH(3)CN, reflux), bromoenoates react with aryl iodides bearing numerous substituents (F, Cl, CF(3), Me, etc.). The expanded description of our initial work as well as the use of polysubstituted aryl iodides is described.
Lautens
M
M
Davenport Laboratories, Department of Chemistry, University of Toronto, Toronto, Ontario, Canada. mlautens@chem.utoronto.ca
Paquin
J F
JF
Piguel
S
S
Dahlmann
M
M