The Fast Photochemical [2+2] Cycloaddition and Reverse Reaction of a Styrylpyrazine Amphiphile in Aqueous Dispersion

Photochemical [2+2] cycloaddition of styrylpyrazine amphiphile 1 in aqueous dispersion occurred quantitatively and much faster than that of stilbene analogue 2. Amphiphile 1 showed intermolecular photoreversible reactivity, [2+2] cycloaddition and the reverse reaction, in aqueous dispersion with alternate irradiation at above 300 and at 254 nm as the first example for 1,2diarylethylene in aqueous dispersion.