A palladium-catalyzed alkynylation of aromatic amines with terminal alkynes via in situ formed trimethylammonium salts is developed. Compared with previous system using ammonium salts as starting materials and high loading of pre-prepared NHC-Pd catalyst (10 mol% Pd), this reaction directly employed amines as the coupling partners and the commercially available Pd2(dba)3/PPh2Cy (1 mol% Pd) as the catalyst
A novel PdCl2-catalyzed oxidative cycloisomerization of 3-cyclopropylideneprop-2-en-1-ones, providing a facile synthesis of highly strained functionalized 2-alkylidenecyclobutanones via furan-fused cyclobutene intermediates, is reported. An interesting route to 2(3H)-furanones with a spiro-cyclopropane unit from the obtained 2-alkylidenecyclobutanones via a ring-contraction rearrangement reaction is