Palladium-catalyzed sequential alkylation–alkenylation reactions: application towards the synthesis of polyfunctionalized fused aromatic rings

Palladium/Norbornene Cooperative Catalysis

“…Unfortunately, aryl bromides and triflates were not suitable coupling partners in this reaction. Variations on the linkers and substitutions were later investigated by the same group. , …”

“…Variations on the linkers and substitutions were later investigated by the same group. 94,95 In 2018, Zhou and co-workers utilized the redox-relay Heck reaction as the termination step to access tetrahydronapthalene (76a−c) and indane (76d) scaffolds (Scheme 43). 96,97 Preliminary studies of the asymmetric version was also described using a chiral phosphoramidite as the ligand, though the enantioselectivity and yield were moderate.…”

Transition metals in organic synthesis: Highlights for the year 2005

“…Palladium catalyzed an alkylation-Heck-type reaction of iodobenzenes in the presence of norbornene to form fused aromatic rings (Eq. (25)) [405].…”

Palladium-catalyzed ring-forming reactions: Methods and applications

“…Various functional groups at different positions on the aryl iodide as well as a variety of Heck acceptors are tolerated [5]. We then showed that a variety of functional groups along the chain on the bromoenoate are compatible, affording highly substituted six-(5) and seven-membered (6) fused aromatic rings in moderate to good yields [6]. This procedure was also extended to the formation of benzoxepines (7) [7].…”

“…Our group modified the reaction conditions and extended the methodology by using a difunctional acceptor (3) so that an intramolecular Heck reaction can follow the ortho alkylation leading to fused aromatic compounds 4 (Scheme 2) [4][5][6][7]. We initially demonstrated that numerous six-and seven-membered fused aromatic carbocycles (5) can be easily prepared using our optimized reaction conditions: iodoarene (1 equiv), Pd(OAc) 2 (10 mol %), tri-2-furylphosphine (22 mol %), Cs 2 CO 3 (2 equiv), norbornene (2 equiv), and bromoenoate (2 equiv) in acetonitrile at 85 °C for 12 h [4].…”