Palladium(II)-catalyzed synthesis of functionalized indenes from o-alkynylbenzylidene ketones.J Org Chem. 2011 Mar 04; 76(5):1491-4.JO
An efficient method for the synthesis of functionalized indenes from o-alkynylbenzylidene ketones under palladium(II) catalysis was developed. The reaction is initiated by trans-nucleopalladation of alkynes, followed by conjugate addition and quenched by protonolysis of the carbon-palladium bond. With acetate and halide ions as nucleophiles, 3-acetoxy- and 3-halogen-substituted indenes could be obtained in high yields.