A highly enantioselective Pd/Cu-catalyzed tandem C–C bond activation/Sonogashira reaction was developed with the aid of new TFSi-Phos, which provided chiral alkynyl indanones in good yields and enantioselectivities.

A palladium-catalyzed asymmetric tandem C–C bond activation/Cacchi reaction between cyclobutanones and o-ethynylanilines was reported. The transient chiral σ-alkylpalladium species generated via enantioselective C­(sp3)–C­(sp2) bond activation of cyclobutanones promotes cyclization of o-ethynylanilines, leading to one-carbon-tethered chiral indanone-substituted indoles. Two C–C bonds and one C–N bond are created with concomitant formation of an all-carbon quaternary stereocenter. Furthermore, a chiral C2-aryl axis can be created in 2,3-disubstituted indole moiety, leading to indanone-substituted indoles with both central and axial stereogenic elements.

A palladium-catalyzed carbonylative C–C bond activation reaction of cyclobutanones is reported, and it affords a variety of indanones bearing ester or amide groups using phenyl formate and benzene-1,3,5-triyl triformate as CO surrogates.

Transition-metal catalyzed C-C bond activation is a formidable challenge owing to the high bond energy. We report here a novel palladium-catalyzed C-C bond activation manner of methylenecyclobutanes followed by subsequent Suzuki cross-coupling reaction affording multisubstituted indanes. The tandem reaction process involves intramolecular carbopalladation of double bond, β-carbon elimination and intermolecular trapping of the transient σ-alkylpalladium complex with boronic acids. A new TADDOL-derived phosphoramidite ligand bearing fluorine and silicon-based bulky groups is found to be efficient for C-C bond activation of methylenecyclobutanes.