Ferric Chloride Catalyzed 1,3-Rearrangement of (Phenoxymethyl)heteroarenes to (Heteroarylmethyl)phenols

Asymmetric Total Synthesis of Neobraclactone C

Asymmetric total synthesis of neobraclactone C was finished for the first time using the convergent synthetic strategy in 22 steps in the longest linear sequence from known materials. The key steps include a steric hindrance/hydrogen bond dual-controlled Heck arylation of α,β-unsaturated ketone to construct hemiketal and cis-alkenyl in one step and a CeCl₃-catalyzed tricycle formation.

Synthesis of Indole/Benzofuran-Containing Diarylmethanes through Palladium-Catalyzed Reaction of Indolylmethyl or Benzofuranylmethyl Acetates with Boronic Acids

The palladium-catalyzed synthesis of indole/benzofuran-containing diarylmethanes starting from indolylmethyl or benzofuranylmethyl acetates with boronic acids has been investigated. The success of the reaction is influenced by the choice of precatalyst: with indolylmethyl acetates the reaction works well with [Pd(η3-C3H5)Cl]2/XPhos while with benzofuranylmethyl acetates Pd2(dba)3/XPhos is more efficient. The good to high yields and the simplicity of the experimental procedure make this protocol a versatile synthetic tool for the preparation of 2- and 3-substituted indoles and 2-benzo[b]furans. The methodology can be advantageously extended to the preparation of a key precursor of Zafirlukast.