A practical synthetic approach to the difluoro-substituted bicyclo[1.1.1]­pentanes was developed. The key step was an addition of difluorocarbene (:CF2) to electron-rich bicyclo[1.1.0]­butanes by the CF3TMS/NaI system. The obtained difluoro-bicyclo[1.1.1]­pentanes are suggested to be used as saturated bioisosteres of benzene rings for the purpose of drug discovery projects.

A novel approach for the stereoselective construction of N–N atropisomeric compounds by a Pd-catalyzed 5-endo-hydroamino-cyclisation is described herein. A broad range of bisheterocycles connected by a configurationally stable N–N stereogenic axis was prepared with catalyst control in enantioenriched form.

The steadily growing interest in substituting precious-metal photoredox catalysts with organic surrogates is vibrantly sustained by emerging methodologies to vary their photochemical behavior. Herein, we report an ad hoc approach for the preparation of acridinium salts with a particularly broad range of photoredox properties. The method involves an aryne–imine–aryne coupling to a linchpin tetrafluoro acridinium salt for a late-stage diversification by nucleophilic aromatic substitution reactions to form diaminoacridinium and undescribed aza-rhodol photocatalysts. The different functionalities and redox properties of the organic acridinium photocatalysts render them suitable for bifunctional photoredox catalysis and organocatalytic photochemical C–N cross-couplings.

A systematic study on the directed Pd-catalyzed (hetero)arylation of 26 substituted cyclic α-amino acids at the C(3)-atom was performed. For the first time, the 7- and 8-membered cyclic amino acids were introduced to C–H activation. 8–Aminoquinoline was used as a directing group.