Homogeneous Pd catalysts have been identified for the conversion of cyclohexenone and tetralone O-pivaloyl oximes to the corresponding primary anilines and 1-aminonaphthalenes. This method is inspired by the Semmler-Wolff reaction, a classic method that exhibits limited synthetic utility owing to its forcing conditions, narrow scope and low product yields. The oxime N–O bond undergoes oxidative addition to Pd0(PCy3)2, and the product of this step has been characterized by X-ray crystallography and shown to undergo dehydrogenation to afford the aniline product.

Organic light-emitting diodes (OLEDs) are the most successful invention of organic electronics in today’s market and have received persistent attention from industrial and scientific communities. OLEDs have rapidly developed into...

Thermally activated delayed fluorescence (TADF) emitters based on a new benzothienopyrimidine acceptor, which is rigid and can form a co-planar structure via hydrogen bonding, were developed as high-efficiency TADF emitters.

Establishment of the structure–property relationships of thermally activated delayed fluorescence (TADF) materials has become a significant quest for the scientific community. Herein, two new donors, 10H‐benzofuro[3,2‐b]indole (BFI) and 10H‐benzo[4,5]thieno[3,2‐b]indole (BTI), have been developed and integrated with a aryltriazine acceptor to design the green TADF emitters benzofuro[3,2‐b]indol‐10‐yl)‐5‐(4,6‐diphenyl‐1,3,5‐triazin‐2‐yl)benzonitrile (BFICNTrz) and 2‐(10H‐benzo[4,5]thieno[3,2‐b]indol‐10‐yl)‐5‐(4,6‐diphenyl‐1,3,5‐triazin‐2‐yl)benzonitrile (BTICNTrz), respectively. The physicochemical and electroluminescence properties of the compounds were tuned by exchanging the heteroatom in the donor scaffold. Intriguingly, the electronegativity of the heteroatom and the ionization potential of the donor unit played vital roles in control of the singlet–triplet energy splitting and TADF mechanism of the compounds. Both compounds showed similar singlet excited states that originated from the charge transfer (CT) states (1CT), whereas the triplet excited states were tuned by the heteroatom in the donor unit. The origin of phosphorescence in the BTICNTrz emitter was CT emission from the triplet state (3CT), whereas that in the BFICNTrz emitter stemmed from the local triplet excited state (3LE). Consequently, BTICNTrz showed a small singlet–triplet energy splitting of 0.08 eV, compared with 0.26 eV for BFICNTrz. Thus, BTICNTrz showed efficient delayed fluorescence with a high quantum yield and a short delayed exciton lifetime, whereas BFICNTrz displayed weak delayed fluorescence with a relatively long lifetime. Furthermore, a BTICNTrz‐based device exhibited a maximum external quantum efficiency (EQE) of 15.2 % and reduced efficiency roll‐off (12 %) compared with its BFICNTrz‐based counterpart, which showed a maximum EQE of 6.4 % and severe efficiency roll‐off (55 %) at a practical brightness range of 1000 cd m−2. These results demonstrate that the choice of subunit plays a vital role in the design of efficient TADF emitters.

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