Enantio‐ and diastereoselective synthesis of trans‐2,3‐disubstituted indanones is achieved by intramolecular hydroacylation of 2‐alkenylbenzaldehydes bearing trisubstituted alkenyl groups under cobalt‐chiral diphosphine catalysis. Notably, a high level of enantioselectivity is induced regardless of the stereochemistry (E/Z ratio) of the alkenyl group of the starting material. Deuterium‐labeling experiments shed light on the productive reaction pathways of the E‐ and Z‐isomers.

A novel TADF emitter showing dual emission is synthesized and applied to OLEDs with an external quantum efficiency of 11.5%.