Synthesis of -acetyl diazocine derivatives via cross-coupling reaction.

Diazocines are photoswitches derived from azobenzenes by bridging the two phenyl rings in position with a CHCH group forming an eight membered (diazocine) ring. Diazocine is superior to most azobenzenes in almost all photophysical properties (switching efficiency, quantum yield, wavelengths etc.).

Substituted nitrogen-bridged diazocines.

Novel nitrogen-bridged diazocines (triazocines) were synthesized that carry a formyl or an acetyl group at the CHNR-bridge and bromo- or iodo-substituents at the distant phenyl ring. The photophysical properties were investigated in acetonitrile and water. As compared to previous approaches the yields of the intramolecular azo cyclizations were increased (from ≈40 to 60%) using an oxidative approach starting from the corresponding aniline precursors.