Sonogashira coupling with aqueous ammonia directed to the synthesis of azotolane derivatives

Sonogashira coupling with aqueous ammonia is tolerable for the reaction of aryl iodides or terminal alkynes bearing an azobenzene group. The reaction of (4-heptyloxyphenyl)ethyne with (4-heptyloxyphenyl)-(4-iodophenyl)diazene in the presence of 1 mol% of PdCl₂(PPh₃)₂, 2 mol% of CuI, and 2 equiv of 0.5 M aqueous ammonia gives the corresponding azotolane in 87% isolated yield after stirring at room temperature for 15 h.     

Two-photon actuation of crosslinked liquid-crystalline polymers utilizing energy transfer system

ABSTRACT

We prepared crosslinked azotolane liquid-crystalline polymer (LCP) films doped with a stilbene derivative (two-photon chromophore) utilizing an interpenetrating polymer network (IPN) structure. The IPN films bend toward the light source upon irradiation with femtosecond laser pulses at 600 nm, which can excite the stilbene derivative by two-photon absorption. The bending speed of the IPN films increases with the square of the laser pulse intensity, which is compelling evidence for the two-photon processes.